[LU-20025] LNet: lnet routing between IPv6 tcp and IPv4 tcp lnets fails

• Type: Bug
• Resolution: Unresolved
• Priority: Medium
• Labels: IPv6 lnet lnet-router
• Severity: 3
• Assignee: Xinxia Qu
• Reporter: Xinxia Qu

Description

If the LNet router is configured to connect an IPv4-based TCP lnet with an IPv6-based TCP lnet, communication between IPv4 and IPv6 endpoints will not work.

C <-tcp(IPv4)-> Router B <-tcp(IPv6)-> A 

The nodes can add the correct routes and successfully ping the router, so the route state is listed as "up" on both sides. However, "lnetctl ping" across the router times out.

Router B shows logs indicating that the IPv6 NID is being truncated. For example, 2006::211:2233:4455:202@tcp6 is truncated to 32.6.0.0@tcp6.

Issue Links

• is related to: LU-18417 Finish IPv6 support