Thread: Multiple networks and routes

i have issues server running syslog-ng. have disabled firewall.

have 2 network interfaces connected 2 different subnets on big lan.
receive syslog events on eth0, , want make sure responses packets coming in way goes out same way. network firewall in front allows incoming syslog traffic.

eth1 interface make default gateway, ip address has network access other parts of network.

if eth0 default gateway, syslog-ng works fine.

if make default route via gateway on eth1 network, not syslog entries. seen on eth0 using tcpdump, reach ip-stack. disappear.

/etc/network/interfaces causes syslog events not arrive. if change other interface has gateway works fine. suggestion on wrong ?

code:

auto eth0 iface eth0 inet static         address 10.215.255.254         netmask 255.255.255.0 #       gateway 10.215.255.1         post-up ip route add 10.215.255.1/32 dev eth1 src 10.215.255.254   auto eth1 iface eth1 inet static         address 10.216.36.254         netmask 255.255.255.0         gateway 10.216.36.1         post-up ip route add 10.216.36.1/32 dev eth1 src 10.216.36.254

since linux per default stupid, , likes send out packets on 1 interface source address other, have been trying iproute2 options, have different routing table traffic coming eth0 aka 10.215.255.254. adding below lines in /etc/network/interfaces, , setting default gw on eth1 instead, syslog not working again.

code:

       post-up ip route add default via 10.215.255.1 table t0        post-up ip rule add 10.215.255.254 table t0

if netcat w/ tcp or udp eth0 ip address host itself, when syslog not logged (i.e. gw on eth1), things logged (with source address of 10.215.255.254 address).

remember had problem once before, can't remember how solved it.

now, machine has limited network access, , can use proxy on eth1 network access stuff.

Forum The Ubuntu Forum Community Ubuntu Official Flavours Support Networking & Wireless [ubuntu] Multiple networks and routes

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