LAN Routing
cancel
Showing results for 
Search instead for 
Did you mean: 

5400zl VRRP shows 2 IP addresses for DHCP requests

thingtwo
Occasional Visitor

5400zl VRRP shows 2 IP addresses for DHCP requests

I have two 5400zl switches setup as Layer3 cores using VRRP.  I have a DHCP server in a subnet which is through another firewall/router (not HP) which gives DHCP to multiple VLANS on the VRRP solution.  DHCP requests are showing both IP addresses of the VRRP cores, and are being responded to accordingly.  Some hosts are having issues showing multiple gateways (BOTH VRRP IPs) during PXE boot, and is breaking other potential protocols across the LAN on multiple VLANS.

 

I like the idea of a redundant routing core, but at what cost?  DHCP is the most basic of Networking protocols.  Why am I seeing requests from both IPs, when I should only see the Master IP?

1 REPLY
Fredrik Lönnman
Honored Contributor

Re: 5400zl VRRP shows 2 IP addresses for DHCP requests

I'm pretty sure that's by design. Since the DHCP DISCOVER is a broadcast it wont be directed specifically to your VRRP-IP, so every vlan interface with a DHCP relay configured will relay that to your DHCP server.

 

Maybe your DHCP server or host cant cope with that? Your host should really be using only the gateway that is sent in the DHCP OFFER from the DHCP server and not care about your VRRP IPs.

---
CCIE Service Provider
MASE Network Infrastructure [2011]
H3CSE
CCNP R&S