Secondary address from a more specific subnet

[Michalis Milaitis]

Hi,

I tried to configure a secondary ipv4 address on BVI interface from a more specific subnet of the primary's address network.

interface BVI6
 ipv4 address 10.112.242.2 255.255.255.0
 ipv4 address 10.112.242.21 255.255.255.248 secondary

When I committed the above configuration the following message appeared and I lost the routing for this subnet :

ipv4_arm[290]: %IP-IP_ARM-6-CFLCT_NO_LONGER : The IPv4 address 10.112.242.2/24 on BVI6 is no longer forced down due to IPv4 address conflicts

The same configuration works properly on 7600 platforms.

Thank you,

Michael

[Michalis Milaitis]

The below is the correct log message, the previous one displayed when I remove the secondary IP from the BVI interface.

RP/0/RSP0/CPU0:Jun  7 11:35:30.526 : ipv4_arm[290]: %IP-IP_ARM-3-CFLCT_FORCED_DOWN : The IPv4 address 10.112.242.1/24 on BVI6 conflicts with other IPv4 addresses and has been forced down

I also forgot to mention that the platform is A9K with ios-xr 4.2.3. I'm sorry for the

misunderstanding.

Thank you,

Michael

[xthuijs · Accepted solution]

Can't do that... a router only allows one interface per subnet defined, so you can never define an interface with a more specific subnet and the address resolution manager (ARM) detects this and blocks that config.

use show arm conflict to identify the origin of the issue.

xander