Youku IPv6 Evolution and Practice Guide

Author: Wu Lingxiao (Gai You)

Evolution route

Phase 1 (late 2020)

At this stage, the IPv6 transformation of all online services is completed, and the access support of IPv6 dual-stack is fully supported; it is integrated into Alibaba Cloud's IPv6 ecosystem, and the intranet environment fully supports IPv4/IPv6 dual-stack; the proportion of IPv6 traffic on the client side is increased, and the IPv6 traffic The proportion is not less than 40% of the total.

Management: The transformation of Youku’s main station WAN, the core network of the group-level data center, and the Internet egress IPv6 network has been fully completed, and IPv6 has been opened in multiple regions and multiple operators. It is not possible to replace core routers and switches that support IPv6 by upgrading. Establish a CDN exclusive resource pool, and select all CDN nodes that support IPv4/IPv6. Introduce IPv6-only dedicated line links to reduce IPv6 access costs in a timely manner;
Cloud: Completely complete the IPv6 transformation of enterprise Internet domain name servers, support AAAA records and IPv6 domain name resolution requests, and configure A and AAAA records for all main core business domain names. Using Alibaba Cloud HTTPDNS service, it supports IPv4/IPv6 dual stack and domain name resolution capability in IPv6-only environment. Youku-related services and interfaces are fully integrated into the cloud, and the newly added ECS, CDN and other resources are all selected from resource products that support IPv6 regions;
Terminal: All mobile phone applications and web browsers support network communication capabilities in IPv4/IPv6 dual stack and IPv6-only environments. Try to introduce a user function experience guidance scheme, so that users can intuitively experience the benefits brought by IPv6. The proportion of IPv6 traffic in the end-side test shall not be less than 40% of the total;
Security: The IPv6 transformation of Youku's Internet egress security protection system has been fully completed, and the security protection plug-ins in the application fully support the IPv6 environment to ensure that the overall security protection capability does not decline. Establish an independent monitoring system under IPv6, covering basic monitoring and application monitoring, with the same monitoring capabilities as IPv4.

Phase II (2021-2022)

This stage fully supports IPv6-only access support; all are integrated into Alibaba Cloud's IPv6-only ecosystem, and the intranet environment fully supports IPv6-only dual-stack; the ratio of IPv6 dual-stack + only is not less than 80%, and the proportion of IPv6 traffic less than 60% of the total.

Guan: Completely complete the IPv6 export transformation of the main station computer room and CDN node computer room, including all mainland and popular overseas nodes. IPv6 traffic runs on dedicated links in an all-round way, fully realizing the traffic profitability under IPv6;
Cloud: Completely complete the IPv6 transformation of enterprise Internet domain name servers, support AAAA records and IPv6 domain name resolution requests, and configure A and AAAA records for all business domain names. All Youku-related services and interfaces use resource products in the IPv6 environment, and the internal network environment is all switched to IPv4/IPv6 dual-stack mode;
Terminal: All terminals and all sites support IPv6-only access for undifferentiated experience. The user product experience design is fully inclined to IPv6, guiding users to replace old facilities and old terminals. The proportion of IPv6 dual-stack users shall not be less than 80%, and IPv6-only mode shall be gradually guided;
Security: Further strengthen the network security capabilities of IPv6, comprehensively improve the protection level, and timely discover and solve the security challenges of new business forms derived from the IPv6 environment. For new fields such as edge computing, Internet of Things, Internet of Vehicles, and cloud games, it has the same level of security assurance capabilities for the entire network.

Phase Three (2023-2025)

At this stage, the transformation of all computer rooms and CDN nodes has been fully completed, and all of them support IPv6-only access; the proportion of IPv6-only is not less than 80%, and the proportion of IPv6 traffic is not less than 80% of the total.

Management: Complete IPv6-only transformation in an all-round way;
Cloud: All products on the cloud are used, and all products support IPv6-only;
End: The IPv6-only ratio is not less than 80%, and the dual-stack mode is eliminated. Provide downgrade services with the minimum feature set for less than 20% of IPv4 users, and encourage upgrades to IPv6-only;
Security: Further strengthen the security protection, security supervision, disaster backup and recovery capabilities in IPv6-only scenarios, and improve the security of entertainment networks, Internet of Things, Internet of Vehicles, cloud computing, cloud games, VR/AI intelligence and other fields in the IPv6 environment ability.

Implementation guide

The internet

Computer room Internet exit

Construction and renovation center computer room IPv6 Internet exit

Following the overall rhythm of Alibaba Group, the central computer room where the core services are located has completed the transformation of the Internet and supports IPv6. In the central computer room where the five major city network exits are located, all of them have been completely transformed to IPv6. The BGP connection method is preferred to facilitate the unified planning of routing protocols within and outside the Internet egress domain. Prepare in advance for IPv6 fee reduction and acceleration, prioritize IPv6 traffic, increase the priority of IPv6 traffic tokens, and prioritize routing in the same environment.

and renovation of CDN node room IPv6 Internet exit

Alibaba Cloud will coordinate the security transformation of regions and time nodes, and conduct business synchronization by region.

Transform and upgrade the backbone network VIP+LVS

Replacing old facilities that do not support IPv6 by upgrading, including a large number of core routers, switches and load balancing equipment. Update the security protection devices such as hardware firewalls and intrusion detection devices in the Internet egress part. Updates are not supported for replacement. Optimize the routing configuration, routing configuration and cache usage ratio, so that the performance of the IPv4 network after the transformation is not degraded, and the performance of the IPv6 network is slightly better than that of the IPv4. Each security protection capability is equal to or better than the protection capability in the IPv4 environment.

Transform and upgrade the application service test environment

The IPv6 link between the production computer room and the test computer room is opened through the tunnel mode, and the proxy server of the enterprise springboard is upgraded to support IPv6, and it supports logging in to the test environment in an IPv6 environment to meet business needs.

Renovation of VPN system of enterprise campus

Together with the Alibaba enterprise intelligent network team, we carried out the transformation of the IT office network, connected to the IPv6 Internet outlet, and upgraded the routers, switches and VPN equipment in the campus. Upgrade the VPN client to support remote login of users in the IPv6 environment, improve the IPv6 security protection strategy in the remote access environment, and strengthen the IPv6 security protection capability.

Domain name resolution DNS/HTTPDNS and fallback

Business domain name network dual stack design and

DNS core upgrade: Enable multi-CNAME capability for business domain names. The business domain names are configured with IPv4-only and IPv6 dual-stack CNAME domain names respectively, with the ability to adjust weights. You can freely control the resolution ratio of IPv4 and IPv6 dual stacks according to regions and operators. The grayscale flow control of IPv6 is performed on the PC/H5 side that uses localdns to realize the coexistence of the IPv4 protocol and the IPv6 protocol. The fallback capability of IPv6->IPv4 is provided by the browser, and some old browsers do not support the fast fallback capability.

HTTPDNS core upgrade: The HTTPDNS service itself is deployed in an IPv6 environment, with IPv6 Internet egress, and provides IPv6 VIP and domain name AAAA resolution guarantees. At the same time, upgrading the HTTPDNS service itself can issue AAAA resolution records to the requested domain name according to the network status of the requesting client and user request parameters, ensuring that the client runs in an IPv6 environment and can normally resolve to the AAAA record of the business domain name.

Rapid fallback of HTTPDNS: When HTTPDNS obtains that the client supports IPv6, it will send the AAAA record and A record of the domain name to the client at the same time. When the client fails to establish an IPv6 connection, it will start to establish an IPv4 connection at the same time to ensure that the user experience is not affected.

At the same time, for some special business domain names, for example, PC-side downgrade is not implemented and the delay caused by downgrade cannot be tolerated. The AAAA record of the business domain name in the authoritative DNS can be removed, and the AAAA record can be configured only in the HTTPDNS, which can meet the requirements of IPv6 on the client side and IPv4 on the PC side.

Dynamic IPv6 proportional control capability

In the early stage of IPv6 construction, the success rate of connection establishment was lower than that of IPv4, and the RT was also higher than that of IPv4, which made it impossible to switch to IPv6 as a whole. At the same time, the part that has been cut may also affect the network quality due to network changes, and it is necessary to temporarily turn off IPv6. If these switching operations are all performed manually by the operation and maintenance students, then it takes 1-2 days to complete an operation with dozens or hundreds of domain names like Youku, which is unacceptable in terms of time rate. Because it is necessary to build a domain name switching system including DNS and HTTPDNS, the configuration of domain names and HTTPDNS can be switched in batches, so that the business of PC and mobile terminal can be synchronized. At the same time, it is necessary to have flexibility when switching, IPv6 is reduced from 100% to 0%, and cannot be cut off all at once. It needs to be executed at 90%-80%-70%----0% to ensure that it will not give network equipment and servers and Network egress brings jumps. At the same time, it is necessary to obtain the monitoring data of the business success rate. If the success rate drops during the switching process, the system can abort the switching or automatically roll back to the previous level, and issue an alarm for the operation and maintenance students to intervene in the investigation.

Network Quality Data Acquisition Design

Client buried point reporting supports IPv6

In the mobile client and PC, the terminal-side operation data and error conditions are usually reported to the collection server by using the buried point technology. Most of the data reports do not take the initiative to bring both IPv4 and IPv6 of the client side, resulting in the server side having no reliable data source to analyze the business situation under IPv6. Therefore, it is necessary to transform the collection server to support IPv6 connection with the client to ensure that the buried point data can be reported normally in the IPv6 dual-stack and IPv6-only environment. At the same time, when the app starts, user authentication, network changes and other scenarios occur, the client's exit IP is actively obtained from the server's response result, and the information is stored in the local cache, and the IP address is brought when the buried point is reported. . In this way, the collection end can collect the real exit IP of the client, and if it has a dual stack, it can also collect IPv4 and IPv6 addresses and automatically associate them. It fundamentally solves the problem that the server cannot obtain IPv4 and IPv6 at the same time in a dual-stack environment, which is helpful for network quality data analysis.

Resource management, operation and maintenance system transformation

Implement IPv4 and IPv6 resource differentiation management capabilities

With the in-depth transformation of IPv6 and policy support, there will be usage scenarios and metering and billing rules that are different from those in the IPv4 environment for resource equipment, traffic bandwidth, and scheduling and drainage that use the IPv6 environment. Slowly, IPv6 will have cost advantages in some application scenarios, and it is recommended to use IPv6 single-stack construction for new support systems such as network management, application performance management, authentication server, DNS/DHCP, etc. on the existing resource management system. It is recommended to carry out dual-stack transformation of the existing support system, which has intelligent operation and maintenance, terminal identification, application identification, intelligent tuning, intelligent roaming, large Data security analysis and other management capabilities, after the network element equipment, applications or users complete the IPv6 single-stack transformation, the support system needs to simultaneously complete the IPv6 single-stack switching.

Achieve independent operation and maintenance capability of IPv6 environment

Transform and enable the dual-stack protocol of the operation and maintenance system, so that the system has the ability to manage dual-stack servers, network devices, application containers, monitoring and collection, database cache middleware, configuration remote push and user data in the IPv6 network environment. For systems and devices that do not support IPv6 temporarily, NAT address translation and IPv4 downgrade are provided for management. After the transformation is completed, IPv6 capabilities will be gradually enabled.

Apps and Services

Interface service and PC page

New application

For the deployment of new applications, select the host computer room resources or Alibaba Cloud regions that support IPv6, and use the dual-stack standard for the export of the computer room to the load balancing.

Web container environment: Select the latest version of Tengine that supports the IPv6 protocol, install the toa module, and support transparent transmission of IPv6 header information to application services.
Development environment and OS system: For application development and compilation, select an operating system that supports the IPv6 protocol, such as Windows server 2003 or later, MAC OS 10 or later, and Linux system CentOS 7 or Alios 7U.
Test environment: The office network environment and the test room are connected through an IPv6 dedicated line. The office network provides IPv6 wireless/wired access points, while retaining the original IPv4 access points. Developers can access the IPv6 access point for daily development and office affairs. When they need to access public network services that do not support IPv6, they can switch to the IPv4 network environment.
Business Scenario 1 IP address database: If the IP address database service is used to locate and determine the user's attribution, it is necessary to upgrade to the latest version of the IP address database data service and have the ability to upgrade regularly. Ensure the accuracy of IPv6 regional attribution judgment.
Business Scenario 2 Uniform IP address format: Because IPv6 addresses can be abbreviated, if the judgment is made directly by strings, IPv6 with and without abbreviations will be judged as not an IP address, resulting in deviations in business processing. . At the same time, some browser requests will automatically abbreviate IPv6 addresses, JAVA network packets, CURL, etc., but will not automatically abbreviate IPv6 addresses, which will increase the complexity of server processing, so it is necessary to prepend a public processing to all IPv6 addresses. Addresses are standardized through public processing to unify business processing logic and reduce inconsistencies between businesses.
Business Scenario 3 IP address storage: In general server log storage, user information storage and other routine processing, the user IP will be stored in the database and other storage. For databases that strictly limit the data type and length, it needs to be defined according to the storage model. , the original IPv4 only needs 32-bit strings or long integer data to save, while IPv6 needs to be expanded to 128 bits, and the long integer cannot be stored, so it needs to be processed by splitting storage of high 64 bits and low 64 bits. .
Business Scenario 3 Interface transfer: When using http get to transfer multiple user IPs in the form of parameters, you need to pay attention to the upper limit of 1024B for get. Originally, when IPv6 is transferred, 10 users are transferred together, but now it is 10 when IPv6 is used. The IP length of each user will exceed the upper limit of get, and you need to use post instead or lower the upper limit.
Business Scenario 4 There is hardcopy of IP addresses: the IP addresses of the upstream and downstream calling interfaces cannot be written directly in the code or in the configuration file, because the time for the upstream and downstream to complete the IPv6 transformation is not exactly the same, and the online time is also inconsistent, which will lead to line failures. failure. All need to be changed to the domain name method.
How to obtain the client IP egress address: In a dual-stack environment, for the same request, you can only obtain one of the IPv4 and IPv6 addresses from the request header, and it is impossible to obtain both. If you want to obtain IPv4 or IPv6 addresses at the same time, you can only choose to repeat the request, or pass the client address through parameters. The request field needs to be expanded, and v4 and v6 are divided into two fields for submission. At the same time, the server also needs to receive and transform.
Log analysis logic: As we all know, in order to facilitate log analysis and disassembly, all business logs will define a unified format, and the fields entered in the log are uniformly separated by delimiters such as || or fixed according to the field length. If you use a separator, you need to consider that you can no longer use:, because this symbol is included in IPv6. When using fixed-length separation, it is also necessary to consider that the IP address can no longer be fixed to 32-bit length, and must be adjusted to 128-bit. At the same time, it must be backward compatible with IPv4, and IPv4 must be supplemented to 128-bit.
Update of the third-party library: Choose a third-party SDK version that supports the IPv6 protocol. If the third-party library is no longer updated to support IPv6, you need to find a replacement solution.
Security deployment environment: Application security services such as access layer security controls, current limiting plug-ins, and ACL whitelist plug-ins should support the IPv6 protocol.
Downgrade capability: It is necessary to consider how to downgrade to IPv4 to continue to provide services when the IPv6 network is unavailable from the business logic.

Stock Application Transformation

Existing applications can be developed for code IPv6 reconstruction or dual-stack support interface development. For those that do not support IPv6 transformation or cannot be transformed temporarily, a small cluster area needs to be separately designated to provide IPv4-only service capabilities.

Access layer transformation: Make an IPv6 upgrade plan, apply for IPv6 VIP, point the load balancing RS to the new IPv6 access layer, and ensure the isolation of IPv4 and IPv6 traffic.
Basic image upgrade: When the original service uses an OS image that is too old and the version is too low, you need to upgrade to the latest basic image that supports IPv6, and use the latest OS for editing and packaging.
Business system transformation: According to the business scenarios of the above-mentioned new applications, the existing business logic is checked. If the above scenarios exist, business code reconstruction and business logic modification are required to make the existing business meet the operating requirements in the IPv6 environment.
Replace the web container environment: upgrade the latest version of Tengine, upgrade the latest toa module, and support transparent transmission of IPv6 header information to application services.
Upgrade the development environment and OS system: Select an operating system that supports the IPv6 protocol for application development and compilation, such as Windows server 2003 or later, MAC OS 10 and later, and CentOS 7 or Alios 7U for Linux systems.

for regression testing in IPv6 test environment

Stock applications are generally tested in a strict IPv4 environment, but there is no guarantee that there will be no problems in IPv6. Therefore, it is necessary to perform regression testing on existing applications and new applications in the IPv6 test environment. Including full-scale testing of all modified function points, as well as coverage testing of unmodified but core function points.

Acceptance

After the application transformation is completed, conduct online grayscale acceptance, and conduct testing and verification in accordance with the relevant requirements of the national website/application IPv6 upgrade and transformation acceptance inspection indicators. , IPv6 security protection and other aspects of testing.

Mobile terminal and APP

Windows/mac IKU application

Access the HTTPDNS service, integrate the HTTPDNS service SDK package on the client side, and the IKU application has the same IPv6 drainage grayscale capability as the mobile client. It replaces the network packet in the IKU application side, and has the network communication capability of IPv6. Develop the degradation capability under IPv6 weak network conditions, switch to IPv4 communication within the delay time acceptable to users, and ensure the loss of user experience. Gradually close the license for low-level OS versions, close the online use of low-version applications, promote OS or device upgrades on the client side, and improve IPv6 usage.

Android/Iphone/Ipad mobile client

This segment accounts for the largest proportion, and the types of user equipment are also the most abundant. It is necessary to reduce the share of the old version through continuous version updates and achieve the goal of increasing the utilization rate of IPv6.

Evaluation of terminal IPv6 support: The terminals installed with Youku APP are classified by model, OS version, performance, and communication capability under IPv6. The newly listed models are verified one by one, and the IPv6 support is evaluated respectively.
Client APP basic package upgrade: The basic network package NetworkSDK and other group two-party packages are upgraded to realize the protocol stack analysis and basic downgrade capabilities that support IPv6. Those who use third-party network libraries, such as libcurl, need to upgrade to the latest version, and at the same time make up for the missing automatic downgrade capability through business logic.
Upgrade IP address: Some APPs integrate a small IP address library. Due to the problem of data packet size, basically no small IP library contains IPv6 data. It is necessary to re-evaluate the relationship between the IP library data packet size and the overall APP packet size. If the integrated IPv6 IP library data packet is too large, the local IP library needs to be replaced by the server-side judgment.
The transformation of the device-side buried point service: The normal reporting of the buried point is the premise of the overall evaluation of service availability and user experience consistency guarantee under IPv6. Especially in the case of weak network, disconnection, and downgrade, the data can be reported normally. Whether the changes in the network environment and the RT changes caused by network switching are correctly detected at the IPv6 buried points, the buried points need to be modified according to the business logic and user operation scenarios.

Large screen OTT side

The hardware replacement rate on the large screen is lower than that on the mobile phone, and a large number of old devices that do not support IPv6 are still in use. The infrastructure used by the large-screen APP needs to be unified with the Android mobile terminal, and the normal use of the IPv6 network environment is supported at the APP level. Refer to the above-mentioned Android mobile terminal for transformation. For the hardware part, those who can support IPv6 by upgrading the OS firmware should actively encourage hardware manufacturers to carry out and push the update. It cannot be supported by upgrading. Considering the overall service cycle and lifespan of the hardware, it will be reminded to update gradually.

Cloud and CDN

Selection of cloud products

New scene

According to Alibaba Cloud's IPv6 transformation plan, select cloud products that have been transformed into regions, and use the business to natively support the IPv6 environment.

stock scene

After a cloud product supports IPv6, the original product needs to be upgraded or replaced before IPv6 support can be enabled. Therefore, there is a migration process for cloud products used in stock. After the traffic needs to be moved to the region where the transformation has been completed, the cloud platform in the original region needs to undergo dual-stack transformation, including ECS, ENV container cluster control center, container orchestration system, VPC/virtual gateway, load balancing, etc. for IPv6 support transformation , release the original resources and re-apply for new IPv6 resources to quickly obtain IPv6 support capabilities. After the transformation is completed, the traffic is gradually switched back to release temporary resources.

IPv6 support for CDNs

Ordinary accelerated domain name

According to the Alibaba Cloud CDN transformation plan, the IPv6 CDN nodes that have been transformed by operators in various regions are added to the scheduling domain. The scheduling algorithm needs to support IPv6 VIP. When the resources of IPv6 nodes in the region are insufficient or there are no IPv6 nodes, whether to perform cross-province and cross-regional scheduling, or downgrade IPv4. From the perspective of user experience, downgrading IPv4 when IPv6 resources are insufficient has little effect on users. You can also calculate the ratio of the CDN bandwidth supporting IPv6 to the total bandwidth, and determine the IPv6 traffic diversion ratio in each region. The Alibaba Cloud console enables the IPv6 function and configures the grayscale ratio of the image domain name. From the traffic entrance, the total amount of grayscale of IPv6 is controlled to ensure that there is no problem of insufficient IPv6 resources or no resources to schedule.

302 scheduling domain name

When the 302 domain name jumps, there will be the problem of the aforementioned IPv6 address abbreviation. The browser will automatically jump with the abbreviated IPv6 address when accessing it. The IPv6 address is requested as-is. Two sets of IPv6 VIPs before the abbreviation and after the abbreviation need to be configured on the 302 node to ensure that the jump can be made in any scenario. In the HTTPS VIP certificate, you need to sign the IPv6 VIP to ensure that the HTTPS can also be jumped normally.

-free domain name

The traffic-free scheduling domain needs to be assigned an IPv6 VIP group, and the IPs of the traffic-free nodes that need to be reported to the operator are included in it, and the IPv6 function can be enabled and disabled to ensure that the IPv6 node is not enabled before the operator's report is completed. , the operator can activate the node in time after the service is completed, avoiding the problem of flow-free failure or high water level in the flow-free scheduling area.

Safety

The overall principle of IPv6 network security: In accordance with different stages of IPv6 evolution, clarify the capability scope and guarantee scheme of IPv6 network security in network, service, application and new business scenarios, strengthen IPv6 security protection capabilities and multi-terminal sharing, edge computing, cloud gaming , Internet of Things and other new business scenarios security protection capabilities.

Current limiting capability

The current limiting capability needs to have the application capability in the IPv4/IPv6 dual-stack scenario, which can limit the total traffic, and can also limit IPv4 and IPv6 respectively. In the case of system capacity saturation, how to prioritize IPv6 request capability to be processed and responded as soon as possible to ensure IPv6-prioritized user experience.

ACL blacklist and whitelist and security policy

Ensure the integrity and efficiency of IPv6 security system protection, and upgrade network security equipment such as firewalls, intrusion detection, behavior auditing, and traffic cleaning to support normal work in the IPv6 environment. With the development of IPv6, the number of IPv6 addresses will far exceed that of IPv4, and the capacity of the existing ACL black and white list will not be satisfied, so it is necessary to expand the capacity in advance. For nodes whose IPv6 security protection capabilities are at risk, network security equipment should be upgraded or replaced. The IPv6 security policy formulation and configuration are carried out from the application business level and the security management level to ensure that the IPv6 security policy includes all IPv4 policies.

IPv6+ innovation

IPv6+5G

With the development of the mobile Internet, more and more devices are connected to the mobile network. To a certain extent, 5G and IPv6 are complementary to each other, and the goals are the same, which is to connect as many devices as possible. Reach the realm of interconnection of all things. IPv6 solves the problem of the limited number of devices on the Internet of Everything. Because of the insufficient number of addresses, IPv4 may not be able to satisfy everyone's access to 10 devices. If you access IPv6, let alone 10 devices per person, 1 billion is no problem. At the same time, 5G solves the problem of the quality of the Internet of Everything, and high speed and low latency are the core advantages of 5G networks. The problems of quantity and quality have been solved by IPv6+5G. Will the era of explosive growth in the demand for mobile devices not come? The technical application of 5G has been greatly satisfied. When the cost is reduced to an appropriate level, IPv6+5G can replace wifi, and NAT address translation is no longer required, and there is no need to switch traffic. As long as the security capabilities are satisfied, you and the world are connected in real time.

IPv6+P2P share

It is conceivable that in the future, every powered device in the home will become a computing center and an entertainment center. Youku will no longer be limited by client devices. Wherever you go, everyone will be a consumer of content and content. The producer of the product, the fragmented time can be used in the most reasonable way, the hands are freed to the greatest extent, and the entertainment feast can be enjoyed anytime, anywhere.

Then this means that a terminal is both a service provider and a service consumer, which not only needs to provide a request entry for other devices, but also actively requests other services. The existing IPv4+NAT solution limits the scope of P2P sharing. In the end, the resources and data that can be shared are very few. The ideal state of IPv6 is that NAT is no longer required for the entire network, and any device can directly request it without address translation. All devices in the network. In this way, the reachable range of P2P is greatly promoted, and resources and data can be covered almost completely. I am for everyone, and everyone is for me, fully in line with our political vision.

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