From 9e5c89cc01f8fe57387bcf0cc28bcc5f1821c5d3 Mon Sep 17 00:00:00 2001 From: Sean Hefty Date: Fri, 6 Jul 2007 10:20:26 -0700 Subject: [PATCH] librdmacm/README: Update readme file to describe two interface problem Signed-off-by: Sean Hefty --- README | 25 +++++++++++++++++++++++-- 1 file changed, 23 insertions(+), 2 deletions(-) diff --git a/README b/README index 28a28b7a..4d104cde 100644 --- a/README +++ b/README @@ -1,7 +1,8 @@ This README is for userspace RDMA cm library. -Building +Building +======== To make this directory, run: ./autogen.sh && ./configure && make && make install @@ -10,8 +11,9 @@ time unless configure.in or Makefile.am changes. Libraries are installed by default at /usr/local/lib. -Device files +Device files +============ The userspace CMA uses a single device file regardless of the number of adapters or ports present. @@ -27,3 +29,22 @@ can be used. This will create the device node named or you can create it manually mknod /dev/infiniband/rdma_cm c 231 255 + + +Common issues +============= + +Using multiple interfaces + The librdmacm does support multiple interfaces. To make use + of multiple interfaces, however, you need to instruct linux + to only send ARP reples on the interface targetted in the ARP + request. This can be done using a command similar to the + following: + + sysctl -w net.ipv4.conf.all.arp_ignore=2 + + Without this change, it's possible for linux to resopnd to ARP + requests on a different interface (IP address) than the IP + address carried in the ARP request. This causes the RDMA stack + to incorrectly map the remote IP address to the wrong RDMA + device. -- 2.41.0