[nSLUG] Multiple IPs with Eastlink
mcurrie at buzz.cs.dal.ca
Mon Feb 18 13:08:19 AST 2002
Eastlink has told me that they cannot map multiple IP addresses to one hwaddr.
I need to firewall 4 IP addresses from Eastlink and do not want to set up 4
firewalls. I can't put more than one physical ethernet card on a subnet.
I've tried that, it doesn't work properly. With MTT i used IP aliasing (eth0,
eth0:0, eth0:1, etc.) and it works beautifully. I can't do this with Eastlink
because the hwaddr remains the same for each alias.
I have been playing with dummy interfaces in hopes of resolving my problem. I
have created a dummy interface on my local network and it works fine. I can
ping it and it can ping the local network. I can assign it the MAC address of
a known ethernet card that is not in use (it isn't even in a computer). When
I create a dummy interface on the Eastlink side, specifying a registered
hwaddr/IP pair, the dummy interface doesn't respond. It can ping itself and
nothing else. I added the dummy interface to the routing table and updated
arp via arp -s xxx.xxx.xxx.xxx FF:FF:FF:FF:FF:FF.
Both the IP of the dummy interface and the IP of the real external interface
are on the same subnet (this may be the problem but I don't know). Does
anyone have any ideas as to how I can either configure the dummy interface to
work OR a different solution to my multiple IP problem with Eastlink?
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