Hello Saverio, Many thanks for the reply, I'll answer your queries below;
On 01/12/16 12:49, Saverio Proto wrote:
Hello, while the problem is in place, you should share the output of ip rule show ip route show table 1 It could be just a problem in your ruleset
Of course, these are those outputs ; root@test1:~# ip rule show 0: from all lookup local 32764: from all to 10.0.16.11 lookup rt2 32765: from 10.0.16.11 lookup rt2 32766: from all lookup main 32767: from all lookup default root@test1:~# ip route show table 1 default via 10.0.16.1 dev eth1 10.0.16.0/24 dev eth1 scope link src 10.0.16.11
and, which one is your webserver ? can you tcpdump to make sure reply packets get out on the NIC with src address 10.0.16.11 ? Saverio
The instance has its two vNICs with source addresses 10.0.0.11 & 10.0.16.11, and the web-server is listening on both.
The HTTP packets do seem to be getting out from 10.0.16.11 as source, but are stopped elsewhere upstream.
I've attached two pcaps showing HTTP reply packets, one from 10.0.0.11 (first vNIC; HTTP request and reply works to a remote client) and one from 10.0.16.11 (second vNIC; HTTP request is sent, reply not received by remote client). In the latter case, the server starts to make retransmissions to the remote client.
Kind regards, Paul Browne
2016-12-01 13:08 GMT+01:00 Paul Browne <pf...@cam.ac.uk>:Hello Operators, For reasons not yet amenable to persuasion otherwise, a customer of our ML2+OVS classic implemented OpenStack would like to map two floating IPs pulled from two separate external network floating IP pools, to two different vNICs on his instances. The floating IP pools correspond to one pool routable from the external Internet and another, RFC1918 pool routable from internal University networks. The tenant private networks are arranged as two RFC1918 VXLANs, each with a router to one of the two external networks. 10.0.0.0/24 -> route to -> 18.104.22.168/23 10.0.16.0/24 -> route to -> 172.24.46.0/23 Mapping two floating IPs to instances isn't possible in Horizon, but is possible from command-line. This doesn't immediately work, however, as the return traffic from the instance needs to be sent back through the correct router gateway interface and not the instance default gateway. I'd initially thought this would be possible by placing a second routing table on the instances to handle the return traffic; debian@test1:/etc/iproute2$ less rt_tables # # reserved values # 255 local 254 main 253 default 0 unspec # # local # #1 inr.ruhep 1 rt2 debian@test1:/etc/network$ less interfaces # The loopback network interface auto lo iface lo inet loopback # The first vNIC, eth0 auto eth0 iface eth0 inet dhcp # The second vNIC, eth1 auto eth1 iface eth1 inet static address 10.0.16.11 netmask 255.255.255.0 post-up ip route add 10.0.16.0/24 dev eth1 src 10.0.16.11 table rt2 post-up ip route add default via 10.0.16.1 dev eth1 table rt2 post-up ip rule add from 10.0.16.11/32 table rt2 post-up ip rule add to 10.0.16.11/32 table rt2 And this works well for SSH and ICMP, but curiously not for HTTP traffic. Requests to a web-server listening on all vNICs are sent but replies not received when the requests are sent to the second mapped floating IP (HTTP requests and replies work as expected when sent to the first mapped floating IP). The requests are logged in both cases however, so traffic is making it to the instance in both cases. I'd say this is clearly an unusual (and possibly un-natural) arrangement, but I was wondering whether anyone else on Operators had come across a similar situation in trying to map floating IPs from two different external networks to an instance? Kind regards, Paul Browne -- ******************* Paul Browne Research Computing Platforms University Information Services Roger Needham Building JJ Thompson Avenue University of Cambridge Cambridge United Kingdom E-Mail: pf...@cam.ac.uk Tel: 0044-1223-46548 ******************* _______________________________________________ OpenStack-operators mailing list OpenStackfirstname.lastname@example.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-operators
-- ******************* Paul Browne Research Computing Platforms University Information Services Roger Needham Building JJ Thompson Avenue University of Cambridge Cambridge United Kingdom E-Mail: pf...@cam.ac.uk Tel: 0044-1223-46548 *******************
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