Hi Steve, tirpc_rpcb_rmtcall is failing. I was able to reproduce it on * openSUSE Tumbleweed with libtirpc 1.3.3 * Debian stable 11 (bullseye) with libtirpc 1.3.1-1 OTOH SLE 15-SP4 with libtirpc 1.2.6 is working. PATH="/opt/ltp/testcases/bin:$PATH" rpc_test.sh -s tirpc_svc_4 -c tirpc_rpcb_rmtcall rpc_test 1 TINFO: initialize 'lhost' 'ltp_ns_veth2' interface rpc_test 1 TINFO: add local addr 10.0.0.2/24 rpc_test 1 TINFO: add local addr fd00:1:1:1::2/64 rpc_test 1 TINFO: initialize 'rhost' 'ltp_ns_veth1' interface rpc_test 1 TINFO: add remote addr 10.0.0.1/24 rpc_test 1 TINFO: add remote addr fd00:1:1:1::1/64 rpc_test 1 TINFO: Network config (local -- remote): rpc_test 1 TINFO: ltp_ns_veth2 -- ltp_ns_veth1 rpc_test 1 TINFO: 10.0.0.2/24 -- 10.0.0.1/24 rpc_test 1 TINFO: fd00:1:1:1::2/64 -- fd00:1:1:1::1/64 rpc_test 1 TINFO: timeout per run is 0h 5m 0s rpc_test 1 TINFO: check registered RPC with rpcinfo rpc_test 1 TINFO: registered RPC: program vers proto port service 100000 4 tcp 111 portmapper 100000 3 tcp 111 portmapper 100000 2 tcp 111 portmapper 100000 4 udp 111 portmapper 100000 3 udp 111 portmapper 100000 2 udp 111 portmapper 100005 1 udp 20048 mountd 100005 1 tcp 20048 mountd 100005 2 udp 20048 mountd 100005 2 tcp 20048 mountd 100005 3 udp 20048 mountd 100005 3 tcp 20048 mountd 100024 1 udp 37966 status 100024 1 tcp 43643 status 100003 3 tcp 2049 nfs 100003 4 tcp 2049 nfs 100227 3 tcp 2049 nfs_acl 100021 1 udp 59603 nlockmgr 100021 3 udp 59603 nlockmgr 100021 4 udp 59603 nlockmgr 100021 1 tcp 39145 nlockmgr 100021 3 tcp 39145 nlockmgr 100021 4 tcp 39145 nlockmgr rpc_test 1 TINFO: using libtirpc: yes rpc_test 1 TFAIL: tirpc_rpcb_rmtcall 10.0.0.2 536875000 failed unexpectedly 1 The problem is in tirpc_rpcb_rmtcall.c [1], which calls rpcb_rmtcall(), which returns 1 (I suppose RPC_CANTENCODEARGS - can't encode arguments - enum clnt_stat from tirpc/rpc/clnt_stat.h): cs = rpcb_rmtcall(nconf, argc[1], progNum, VERSNUM, PROCNUM, (xdrproc_t) xdr_int, (char *)&var_snd, (xdrproc_t) xdr_int, (char *)&var_rec, tv, &svcaddr); test_status = (cs == RPC_SUCCESS) ? 0 : 1; //This last printf gives the result status to the tests suite //normally should be 0: test has passed or 1: test has failed printf("%d\n", test_status); return test_status; Any idea what could be wrong with these very old tests? Kind regards, Petr [1] https://github.com/linux-test-project/ltp/blob/12765c115f11026c090ab0ee5dd79b38d95ef31f/testcases/network/rpc/rpc-tirpc/tests_pack/rpc_suite/tirpc/tirpc_expertlevel_rpcb_rmtcall/tirpc_rpcb_rmtcall.c#L91-L93