Messages in this thread | | | Subject | Re: some trouble when using vrf | From | linmiaohe <> | Date | Tue, 16 Apr 2019 22:16:22 +0800 |
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On 2019/4/16 20:11, Mike Manning wrote: > On 16/04/2019 12:26, linmiaohe wrote: >> Hi all: >> I meet some trouble when using vrf, it's very nice of you if you >> can help me fix it. >> >> 1.If I bind a vrf address before I set SO_BINDTODEVICE opts to bind an >> enslaved device, "Cannot assign requested address" will occurs. It's >> because only after we set SO_BINDTODEVICE opts to bind an enslaved device, >> then we can lookup the route in the specified l3mdev domain. >> I think we couldn't limit the order of bind ip addr and SO_BINDTODEVICE opts >> otherwise many vrf unaware apps many need to change their code. >> I can't find a convenient way to fix it.Here is an example: >> >> ... >> bind(sock_fd, (struct sockaddr *)&addr_serv, sizeof(addr_serv)); >> ... >> ret = setsockopt(sock_fd, SOL_SOCKET, SO_BINDTODEVICE, bind_dev, strlen(bind_dev)+1); >> ... >> This code snipet doesn't work if the ip address of addr_serv is not in default vrf. And >> "Cannot assign requested address" will occurs. > Or you can run instances of vrf-unaware applications per VRF with 'sudo > ip vrf exec <vrf> <cmd>', with the 3 sysctl you indicate below set to 0. >> 2.When I run a udp server in default vrf and set net.ipv4.udp_l3mdev_accept=1, >> it's supposed to work accorss VRFs. >> But it occurs when udp server received a packet, it sends back with the source >> ip address from default vrf which is supposed to from the specified l3mdev domain. >> And the connection between server and client is broken. It's because udp server >> run in default vrf and doesn't bind the enslaved device, so only the route table in >> default vrf is avaliable. >> >> For example,I run a udp server in default vrf and set net.ipv4.udp_l3mdev_accept=1: >> [root@localhost vrf]# sysctl -a | grep l3mdev >> net.ipv4.raw_l3mdev_accept = 1 >> net.ipv4.tcp_l3mdev_accept = 1 >> net.ipv4.udp_l3mdev_accept = 1 >> >> Then connect the server and send a udp packet to the specified vrf. Here is tcpdump output: >> 17:28:54.925417 IP 10.0.0.2.43003 > 10.0.0.1.irdmi: UDP, length 17 >> 17:28:54.925953 IP 9.85.153.236.irdmi > 10.0.0.2.43003: UDP, length 17 >> ps. 10.0.0.2 is client ip, 10.0.0.1 is specified vrf ip, and 9.85.153.236 is default vrf ip. >> 10.0.0.1 and 9.85.153.236 are in the same host. >> >> Thanks a lot if you can help me fix these. Have a nice day. >> >> >> > > > . > Thanks for your reply. Run instances of vrf-unaware applications per VRF is an optional solution for problem 1. But maybe it will limits the applications supposed to accross VRFS can't coexist with per VRF applications as udp_l3mdev_accept is globally effective. And what about problem 2? Thanks again.
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