[AI Generated] perf(ntttcp): run ntttcp/lagscope over internal IPv4 on dual-stack (use_ipv6)

[LiliDeng]

Problem

perf_tcp_ntttcp_sriov (and the other perf_*_ntttcp_* cases) fail on every
attempt when the environment is deployed with IPv6 (use_ipv6: true):

Error during ntttcp test for 1 connections: no port opened for lagscope server
...
LisaException: ntttcp test for 1 connections failed after 20 attempts.

Root cause: ntttcp and lagscope bind/connect over IPv4 only. On a dual-stack
(use_ipv6) deployment server.internal_address is the IPv6 private address, so
lagscope -r<ipv6> never opens its listening port and every ntttcp attempt
fails. The nodes still have an internal IPv4 on the same (SRIOV) NIC.

Fix

Resolve the server's internal IPv4 from its primary NIC and use it as the
ntttcp/lagscope target when internal_address is IPv6. IPv4-only deployments are
unaffected — internal_address is already IPv4, so the helper returns it
unchanged and every call site behaves exactly as before.

Validation

perf_tcp_ntttcp_sriov on Azure (eastus2, Ubuntu 22.04, Standard_D2ads_v5,
2 nodes, SRIOV):

• IPv6 deploy + IPv4 ntttcp (use_ipv6: true): PASSED. Logs show
  lagscope -r10.0.0.4 → TCP 10.0.0.4:6001 (LISTEN) and ntttcp -s10.0.0.4;
  throughput collected (e.g. 3.77 Gbps @ 20480 connections). The VM is dual-stack
  (inet 10.0.0.5, inet6 2001:db8::5).
• IPv4 (use_ipv6: false): unchanged code path (server_comm_address == server.internal_address), no regression.

Lint

black --check, flake8, pylint (10.00/10) clean on the changed file; mypy
only reports the pre-existing retry import-untyped and unrelated type: ignore
notes.

[Copilot]

Pull request overview

This PR addresses consistent failures in perf_*_ntttcp_* runs on dual-stack (use_ipv6: true) environments by ensuring ntttcp/lagscope target an internal IPv4 address when server.internal_address is an IPv6 address.

Changes:

• Added an internal helper to resolve an IPv4 address for ntttcp/lagscope when the node’s internal_address is IPv6.
• Updated perf_ntttcp() to use the resolved IPv4 address for lagscope and ntttcp client/server targeting.

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 1 comment.

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 2 comments.