On Mon, 28 Oct 2002, fooler wrote: > ----- Original Message ----- > From: "Rikki T. Vizcarra" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Sent: Monday, October 28, 2002 1:29 PM > Subject: [plug] question on routing using 2 gateways > > > > My question is, how come, when I route to ISPONE gateway, both connections > > are perfectly fine? But when I route to ISPTWO gateway, only ISPTWO > > connection can be seen!? > > what happening here is that ispone ip block is still routable for outgoing > traffic going to isptwo(except if your isptwo or its ascendants implemented > ingress filtering where to allow only to pass those ip addresses known to > them and drop it otherwise).... upon returning (where the source ip address > is now the destination ip address), it will pass thru to ispone and not to > isptwo... in case you temporarily down your ispone link, you will not > receive any packets coming from ispone segment block even if you change > their default gateway to isptwo... >
Correct. So to get routing up on both interfaces you need to use 'route by source', and ip rules for instance: ip route add default via gw-of-isp1 dev eth0 table 90 ip route add default via gw-of-isp2 dev eth1 table 91 ip rule add from ip-address-of-isp1/32 lookup 90 ip rule add from ip-address-of-isp2/32 lookup 91 This way both your interfaces will respond when they are connected to regardless of what is the default route. HTH _ Philippine Linux Users Group. Web site and archives at http://plug.linux.org.ph To leave: send "unsubscribe" in the body to [EMAIL PROTECTED] Fully Searchable Archives With Friendly Web Interface at http://marc.free.net.ph To subscribe to the Linux Newbies' List: send "subscribe" in the body to [EMAIL PROTECTED]
