[LU-14386] LNet: select reachable remote peer nid

• Type: Bug
• Resolution: Unresolved
• Priority: Minor
• Affects Version/s: Lustre 2.12.6
• Labels: lnet lnet-router
• Severity: 3
• Assignee: Serguei Smirnov
• Reporter: Serguei Smirnov

Description

 The following results in a problem:

NodeA --tcp0-- GW --tcp1-- NodeB 

------ NodeA ------
lnetctl net show
    - net type: tcp9
      local NI(s):
        - nid: 192.168.122.10@tcp9
    - net type: tcp
      local NI(s):
        - nid: 192.168.122.142@tcp

------ NodeB ------
lnetctl net show
net:
    - net type: tcp1
      local NI(s):
        - nid: 192.168.122.40@tcp1

------ NodeB ------
lnetctl peer show
peer:
    - primary nid: 192.168.122.10@tcp9
      Multi-Rail: True
      peer ni:
        - nid: 192.168.122.142@tcp
          state: NA
        - nid: 192.168.122.10@tcp9
          state: NA

Note that NodeB lists NodeA under the unreachable tcp9 primary nid. Even though NodeB is aware of the reachable nid for NodeA, it gets confused if using the primary nid:

------ NodeB ------
lnetctl ping 192.168.122.10@tcp9
manage:
    - ping:
          errno: -1
          descr: failed to ping 192.168.122.10@tcp9: Input/output error

Issue Links

• is related to: LU-13548 LNet: b2_12 discovery of non-MR peers may yield unreachable peer NIs