Hi Ajesh, Thanks for the explanation. When you have "accept mode" enabled on a VR and that VR enters the master state, the virtual IP addresses get added on the interface. From your description, it seems like the ARP/neighbor resolution code is using the newly added IP address as the sender protocol address in ARP requests rather than other addresses which were already configured on the interface. I'll have to look into how that could be fixed.
Some possible workarounds for the time being: - Don't enable accept mode on the VR. If VRRP does not add the virtual IP address to the interface, it will not be used in ARP requests. - Create a static entry in the neighbor table for the gateway. -Matt On Fri, Feb 25, 2022 at 5:08 AM <ajesh...@gmail.com> wrote: > Hi Matt, > > Thanks for the reply. > We are(i am working with Mechthild) using an Ericsson R6K > router(bridge/bvi on the router). > > The VPP VRRP master indeed sends GARP at start up with the right VRRP MAC > address, so are the VRRP periodic advertisements using the correct virtual > MAC. > However, when it has to resolve the GW address it sends out ARP requests > using the VIP and with the sender MAC as the physical interface MAC, > > like in this packet Mechthild has shown (172.17.1.3 is the VIP and .126 is > the GW ) > > 22:33:52.620143 78:ac:44:1f:47:60 > ff:ff:ff:ff:ff:ff, ethertype 802.1Q > (0x8100), length 46: vlan 101, p 0, ethertype ARP, Ethernet (len 6), IPv4 > (len 4), Request who-has 172.17.1.126 tell 172.17.1.3, length 28 > > Frame 8: 64 bytes on wire (512 bits), 64 bytes captured (512 bits) > Ethernet II, Src: Dell_1f:47:60 (78:ac:44:1f:47:60), Dst: Broadcast > (ff:ff:ff:ff:ff:ff) > 802.1Q Virtual LAN, PRI: 0, DEI: 0, ID: 101 > Address Resolution Protocol (request) > Hardware type: Ethernet (1) > Protocol type: IPv4 (0x0800) > Hardware size: 6 > Protocol size: 4 > Opcode: request (1) > Sender MAC address: Dell_1f:47:60 (78:ac:44:1f:47:60) <<<<<<<<<< > Sender IP address: 172.17.1.3 > Target MAC address: 00:00:00_00:00:00 (00:00:00:00:00:00) > Target IP address: 172.17.1.126 > > This causes the R6K to update the ARP/bridge table. > > The RFC states that, > > When a VRRP router restarts or boots, it SHOULD NOT send any ARP > messages using its physical MAC address for the IPv4 address it owns; > it should only send ARP messages that include virtual MAC addresses. > > > However it is not mentioning about regular operation - but logically it > should still work the same way, or? > > Thanks and best regards, > Ajesh > > > > >
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