diff --git a/src/common/config_opts.h b/src/common/config_opts.h
index 5a6f54f7f20..6b7a90e5005 100644
--- a/src/common/config_opts.h
+++ b/src/common/config_opts.h
@@ -224,7 +224,7 @@ OPTION(ms_async_rdma_receive_buffers, OPT_U32, 10240)
 OPTION(ms_async_rdma_port_num, OPT_U32, 1)
 OPTION(ms_async_rdma_polling_us, OPT_U32, 1000)
 OPTION(ms_async_rdma_local_gid, OPT_STR, "")       // GID format: "fe80:0000:0000:0000:7efe:90ff:fe72:6efe", no zero folding
-OPTION(ms_async_rdma_roce_ver, OPT_INT, 2)         // 2=RoCEv2, 1=RoCEv1.5, 0=RoCEv1
+OPTION(ms_async_rdma_roce_ver, OPT_INT, 1)         // 0=RoCEv1, 1=RoCEv2, 2=RoCEv1.5
 OPTION(ms_async_rdma_sl, OPT_INT, 3)               // in RoCE, this means PCP
 
 OPTION(ms_dpdk_port_id, OPT_INT, 0)
diff --git a/src/msg/async/rdma/Infiniband.cc b/src/msg/async/rdma/Infiniband.cc
index 2913aa1ecc4..d81c338d2a2 100644
--- a/src/msg/async/rdma/Infiniband.cc
+++ b/src/msg/async/rdma/Infiniband.cc
@@ -49,7 +49,8 @@ Device::Device(CephContext *cct, ibv_device* d): device(d), device_attr(new ibv_
 Port::Port(CephContext *cct, struct ibv_context* ictxt, uint8_t ipn): ctxt(ictxt), port_num(ipn), port_attr(new ibv_port_attr) {
    union ibv_gid cgid;
    struct ibv_exp_gid_attr gid_attr;
-
+   bool malformed = false;
+
    int r = ibv_query_port(ctxt, port_num, port_attr);
    if (r == -1) {
      lderr(cct) << __func__  << " query port failed  " << cpp_strerror(errno) << dendl;
@@ -61,7 +62,7 @@ Port::Port(CephContext *cct, struct ibv_context* ictxt, uint8_t ipn): ctxt(ictxt
    // search for requested GID in GIDs table
    ldout(cct, 1) << __func__ << " looking for local GID " << (cct->_conf->ms_async_rdma_local_gid)
        << " of type " << (cct->_conf->ms_async_rdma_roce_ver) << dendl;
-   sscanf(cct->_conf->ms_async_rdma_local_gid.c_str(),
+   r = sscanf(cct->_conf->ms_async_rdma_local_gid.c_str(),
        "%02hhx%02hhx:%02hhx%02hhx:%02hhx%02hhx:%02hhx%02hhx"
        ":%02hhx%02hhx:%02hhx%02hhx:%02hhx%02hhx:%02hhx%02hhx",
      &cgid.raw[ 0], &cgid.raw[ 1],
@@ -73,6 +74,11 @@ Port::Port(CephContext *cct, struct ibv_context* ictxt, uint8_t ipn): ctxt(ictxt
      &cgid.raw[12], &cgid.raw[13],
      &cgid.raw[14], &cgid.raw[15]);
 
+   if (r != 16) {
+     ldout(cct, 1) << __func__ << " malformed or no GID supplied, using GID index 0" << dendl;
+     malformed = true;
+   }
+
    gid_attr.comp_mask = IBV_EXP_QUERY_GID_ATTR_TYPE;
 
    for (gid_idx = 0; gid_idx < port_attr->gid_tbl_len; gid_idx++) {
@@ -86,6 +92,8 @@ Port::Port(CephContext *cct, struct ibv_context* ictxt, uint8_t ipn): ctxt(ictxt
        lderr(cct) << __func__  << " query gid attributes of port " << port_num << " index " << gid_idx << " failed  " << cpp_strerror(errno) << dendl;
        ceph_abort();
      }
+
+     if (malformed) break; // stay with gid_idx=0
      if ( (gid_attr.type == cct->_conf->ms_async_rdma_roce_ver) &&
 	   (memcmp(&gid, &cgid, 16) == 0) ) {
 	ldout(cct, 1) << __func__ << " found at index " << gid_idx << dendl;