Troubleshooting aliases.

[Colin Waring]

Hi folks,
Been running into brick walls since last night on this one.
Situation is that our server has 6.1-RELEASE on it with four IP addresses.

The section of rc.conf is this:

ifconfig_em0="inet a.a.a.a netmask 255.255.255.0"
ifconfig_em0_alias0="inet a.a.a.b netmask 255.255.255.255"
ifconfig_em0_alias1="inet a.a.a.c netmask 255.255.255.255"
ifconfig_em0_alias2="inet a.a.a.d netmask 255.255.255.255"

For some reason, with no updates or changes both a.a.a.b and a.a.a.c have
stopped working properly. a.a.a.a works fine, as does a.a.a.d.

Unfortunately, the nameservers for the domains hosted on the server use
a.a.a.b and a.a.a.c!

So basically I can't figure out what's up as .d works fine..anyone able to
help me with some suggestions of where to look for fixing .b and .c?