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sanantonio030800

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IP aliases appear rejected by ADSL modem

My Redhat 6.1 (2.2.13 kernel) system is configured as a firewall and has several IP aliases on the public side.  IP MASQ via ipchains works fine: I can reach everywhere from the private side of the firewall.  My ISP is providing 8 static IP addresses.

The problem is that only one public IP (whichever one is assigned to the firewall as its primary IP address) gets to the Internet most of the time.  The remaining 7 addresses are invisible from the Internet although I can ping them reliably from the private side of the firewall and from the firewall machine itself.

The ADSL modem is an Alcatel "Home" model with forwarding enabled.  Its IP address is 10.0.0.138.  When I ping it with a version of ping that allows me to set the source IP address, it responds only to the primary IP address most of the time.  What is really confusing is that at one point I could ping with the entire range of 8 addresses and it would respond to all of them.  

The question is, why doesn't it do that all the time and how can I encourage it to do so reliably?
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jlevie

I need a bit more information, what are the 8 static addresses (probably a netblock of 8, I'd imagine).
Avatar of sanantonio030800

ASKER

The 8 static addresses are a block of 8 with netmask 255.255.255.0: xxx.xxx.xxx.208-215.  Thanks.
Close, I have to have the actual IP's to try a traceroute to them. If you don't want them to be visible in a public forum, email them to jlevie@bellsouth.net.

FYI, the netmask has to be 255.255.255.252 for a netblock of 8.
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sanantonio030800

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Hello everyone,

I am moving this question to the PAQ.

-- I am accepting one of sanantonio's comments as an answer --

darinw
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