[lustre-discuss] Lustre Client pinned to use specific NIC on host

[Horn, Chris]

You can use a local network user-defined selection policy (UDSP) to assign a priority to a local interface. This does not guarantee that LNet will only​ use that interface, but it will prefer it over other, lower-priority interfaces.

# lnetctl net show -v --net tcp | grep -e send_count -e recv_count -e nid
      -     nid: 172.18.2.5 at tcp
                  send_count: 0
                  recv_count: 0
      -     nid: 172.18.2.1 at tcp
                  send_count: 0
                  recv_count: 0
# lnetctl udsp add --src 172.18.2.1 at tcp --priority 0
# lst.sh -t 172.18.2.2 at tcp -f 172.18.2.5 at tcp -m rw
…
brw_rw is running now
…
# lnetctl net show -v --net tcp | grep -e send_count -e recv_count -e nid
      -     nid: 172.18.2.5 at tcp
                  send_count: 14
                  recv_count: 14
      -     nid: 172.18.2.1 at tcp
                  send_count: 162088
                  recv_count: 224920
#



Chris Horn

From: lustre-discuss <lustre-discuss-bounces at lists.lustre.org> on behalf of Sonia Sharma via lustre-discuss <lustre-discuss at lists.lustre.org>
Date: Friday, October 3, 2025 at 1:47 PM
To: lustre-discuss <lustre-discuss at lists.lustre.org>
Subject: [lustre-discuss] Lustre Client pinned to use specific NIC on host

Hello Dear Lustre Community

I was wondering if there is some setting/way to make a Lustre Client use only a specific NIC to route its LNet messages from even when multiple NICs on that host are configured with the same LNet network.

For example, let’s say I have a host with this below LNet configuration, then is there a way that I can have the Lustre client to use only “10.30.201.26 at tcp” for all its communication

[node1]# lnetctl net show
net:
    - net type: lo
      local NI(s):
        - nid: 0 at lo
          status: up
    - net type: tcp
      local NI(s):
        - nid: 10.30.201.26 at tcp
          status: up
          interfaces:
              0: enp1s0
        - nid: 10.30.201.10 at tcp
          status: up
          interfaces:
              0: enp1s0:10269
        - nid: 10.30.202.241 at tcp
          status: up
          interfaces:
              0: enp1s0:10257

Best regards
Sonia


Confidential – Oracle Internal
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