IP Alias and NAT problems

Hi Friends,

Actually I have a firewall running RedHat 8 with almost the latest kernel (from RH). The interface eth0 has many aliases and there is a nat rule:

iptables -t nat -A POSTROUTING -s 10.x.x.x/16 -j SNAT --to-source 200.x.x.10-200.x.x.21

(200.x.x.10-200.x.x.21 are IP aliases)

Everthing works fine, but when I try to do the same on RedHat9 (other box) running the latest kernel it doesnt works. Only works with the IP address of the interface (no alias), like this:

iptables -t nat -A POSTROUTING -s 10.x.x.x/16 -j SNAT --to-source 200.x.x.9

What is happening? why dont works SNAT with aliases? or maybe is not a netfilter problem?

Thanks in advance.

Geffrey Velásquez.

Friends,

Additionaly, the Redhat9 Firewall is an IBM xSeries 345, it has 3 intefaces NetXtreme 1000 T, 2 integrated Intel Ethernet 1000 and a 3con 10/1000

alias eth0 3c59x
alias eth1 tg3
alias eth2 tg3
alias eth3 tg3
alias eth4 e1000
alias eth5 e1000

Maybe could be the tg3 driver that is failing with ip alias?