Hi, I have configured one of my Mellanox network adapters for RoCE: --- CA 'roceP1p1s0f1' CA type: MT4123 Number of ports: 1 Firmware version: 20.32.1010 Hardware version: 0 Node GUID: 0xb8cef603002d1707 System image GUID: 0xb8cef603002d1706 Port 1: State: Active Physical state: LinkUp Rate: 100 Base lid: 0 LMC: 0 SM lid: 0 Capability mask: 0x00010000 Port GUID: 0xbacef6fffe2d1707 Link layer: Ethernet --- The Infiniband stack was installed from the official Ubuntu repository (20.04.4 LTS): --- $ apt search ibverbs Sorting... Done Full Text Search... Done ibverbs-providers/focal,now 28.0-1ubuntu1 arm64 [installed] User space provider drivers for libibverbs ibverbs-utils/focal,now 28.0-1ubuntu1 arm64 [installed] Examples for the libibverbs library libibverbs-dev/focal,now 28.0-1ubuntu1 arm64 [installed] Development files for the libibverbs library libibverbs1/focal,now 28.0-1ubuntu1 arm64 [installed] Library for direct userspace use of RDMA (InfiniBand/iWARP) librdmacm-dev/focal,now 28.0-1ubuntu1 arm64 [installed] Development files for the librdmacm library librdmacm1/focal,now 28.0-1ubuntu1 arm64 [installed] Library for managing RDMA connections rdmacm-utils/focal,now 28.0-1ubuntu1 arm64 [installed] Examples for the librdmacm library --- When I start the ucmatose server with the address format "gid", the tool fails binding with the error "No such device" Here is an example of the output: --- $ cat /sys/class/infiniband/roceP1p1s0f1/ports/1/gids/0 fe80:0000:0000:0000:bace:f6ff:fe2d:1707 $ ucmatose -b fe80:0000:0000:0000:bace:f6ff:fe2d:1707 -P ib -f gid cmatose: starting server cmatose: bind address failed: No such device test complete return status -1 --- Does rdmacm support connection establishment using GID with RoCE? Or Is it a known limitation for RoCE? FYI, the same experiment without RoCE (Link layer: Infiniband) works perfectly. Thanks for your help and your feedback. Sylvain Didelot