Dear Michael, It is completely normal for a router data plane to forbid this scenario. Given a packet to route to 13.13.13.114, which interface should the data plane choose?
>From what I can tell, it looks like you’re trying to route untagged as well as >VLAN 11 and VLAN 12 packets. This sounds like an IRB use case to me. Please >see >https://wiki.fd.io/view/VPP/Command-line_Interface_(CLI)_Guide#VLAN_Tag_Rewrite HTH... Dave From: vpp-dev@lists.fd.io <vpp-dev@lists.fd.io> On Behalf Of Michael Yu Sent: Monday, August 13, 2018 10:48 PM To: vpp-dev <vpp-dev@lists.fd.io> Cc: Neale Ranns (nranns) <nra...@cisco.com>; Ole Troan <otr...@employees.org> Subject: Re: [vpp-dev] Overlapping IP/subnet support on base/vlan interface Hello, I have checked the latest code in master branch and confirm ” VPP does not support multiple interfaces in the same subnet” is still true. And I can understand the commit https://gerrit.fd.io/r/#/c/8057/ is to expand the check of overlapping subnet to all interfaces in the same table/VRF. >From draft check and previous discussion I can also understand that the >limitation is that only one fib entry (the latter one) can exist in the fib >table for one given subnet, but I am not sure if this is the only place >limitation exists. And from what I see there is no plan to support “multiple interfaces in the same subnet” configuration. Could you help confirm my understanding? Thanks. Actually overlapping IP configuration is one of use cases we want to support in our project so we want to understand the limitation and to see how we can handle it, thanks for your help. Best Regards Michael From: Yu, Michael A. (NSB - CN/Qingdao) Sent: 2018年8月13日 14:51 To: 'Neale Ranns' <nra...@cisco.com<mailto:nra...@cisco.com>>; vpp-dev <vpp-dev@lists.fd.io<mailto:vpp-dev@lists.fd.io>> Subject: Overlapping IP/subnet support on base/vlan interface Hello Neale and VPP experts, We have one use case to support in VPP, to configure overlapping IP on flat interface and VLAN sub-interface, like below: Eth1 -- 13.13.13.114 Eth1.11 -- 13.13.13.114 Eth1.12 -- 13.13.13.114 But we found that this kind of configuration is not supported yet and below error would be printed after we configure one IP on the flat interface and when we configure the same IP on the vlan sub-interface. (we are using 18.01) [root@localhost tools]# vppctl set int ip addr host-veth1.111 13.13.13.114/24 set interface ip address: Prefix 13.13.13.114/24 already found on interface host-veth1 We made some search and found in attached email it’s claimed ” VPP does not support multiple interfaces in the same subnet.” and https://gerrit.fd.io/r/#/c/8057/ was submitted to forbid this kind of configuration. Our questions are that: 1. If the statement ” VPP does not support multiple interfaces in the same subnet” is still true in latest implementation? (my assumption is yes) 2. Is there any plan to support this kind of configuration (overlapping subnet or IP on flat interface and vlan sub-interface) in the future? 3. Do you know where this limitation comes from? we want to understand the feasibility to break this limitation. Could you help? Thanks! Best Regards Michael
-=-=-=-=-=-=-=-=-=-=-=- Links: You receive all messages sent to this group. View/Reply Online (#10140): https://lists.fd.io/g/vpp-dev/message/10140 Mute This Topic: https://lists.fd.io/mt/24500872/21656 Group Owner: vpp-dev+ow...@lists.fd.io Unsubscribe: https://lists.fd.io/g/vpp-dev/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
