RE: How to set-up two 'defaultrouter' IPs?
Much appreciated. : ) -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] On Behalf Of Kevin Stevens Sent: January 29, 2003 3:55 PM To: Lowell Gilbert Cc: [EMAIL PROTECTED] Subject: Re: How to set-up two 'defaultrouter' IPs? On Wed, 29 Jan 2003, Lowell Gilbert wrote: Does that make sense? Sure. What you want isn't two default routers, because at any given time there's only one way you want to route this traffic. What you really want is to change default router when the outside world sees one as down. A little tricky, because the system itself might not see main network as problematic, even though the rest of the Internet does. Not multiple default routers, but multiple default routes, in this case two, with different metrics to control failover. This is easy to do on some systems (Cisco and Solaris), not so on others. Don't know about FreeBSD, but I'll take a look later if the question hasn't been answered already. KeS To Unsubscribe: send mail to [EMAIL PROTECTED] with unsubscribe freebsd-questions in the body of the message To Unsubscribe: send mail to [EMAIL PROTECTED] with unsubscribe freebsd-questions in the body of the message
Re: How to set-up two 'defaultrouter' IPs?
Kevin Stevens [EMAIL PROTECTED] writes: Not multiple default routers, but multiple default routes, in this case two, with different metrics to control failover. This is easy to do on some systems (Cisco and Solaris), not so on others. Don't know about FreeBSD, but I'll take a look later if the question hasn't been answered already. Okay, that makes more sense. For that, you generally use a routing protocol, but you need some cooperation from your service provider(s). To Unsubscribe: send mail to [EMAIL PROTECTED] with unsubscribe freebsd-questions in the body of the message
RE: How to set-up two 'defaultrouter' IPs?
See reply below... To create a somewhat redundant network connection, my friend has connected to business level ADSL connections at his home (32 IPs each). So, he has two routers, on two different networks (ATT/UUNET) and what he's doing is multi-homing his NIC cards and via some interesting DNS set-up, theoretically, there is some network redundancy or failover or something. Anyway, here's the question... how would I set-up two 'defaultrouter' IPs in my rc.conf? Is that were I would do such a thing? I'd like to have the same scenario that he's building with a multi-homed NIC and two IPs per VirtualHost directive. I guess there are actually many steps to accomplish this (as I now start to think about it) but I'm wondering how to set-up the networking piece first. Many thanks in advance, Two truly default routes is not really sensical. You generally play games based on source address, TCP port, or something like that, and make sure that they NAT separately. [It has to involve NAT, because for networks that small, you can't get routes distributed widely enough to do true multihoming.] So the answer depends on exactly what hack you want to do. What I'd like to do is this... right now my NIC answers 212.12.12.212 (for instance) externally and that's the address I use for Apache's NameVirtualHost directives. I would also like my NIC to answer on 252.12.12.212 (second network connection) and serve the same VirtualHost directives... So, what happens is, in NS1.NAMESERVER.NET (which is on the 212 network) the A record for my box is 212.12.12.212 and, if that network should fail, the requests will be answered by NS2.NAMESERVER.NET (which is on the 252 network) and it has an A record for my box of 252.12.12.212. So, in effect, the name server's availability actually directs the traffic to the available network connection. Does that make sense? p. To Unsubscribe: send mail to [EMAIL PROTECTED] with unsubscribe freebsd-questions in the body of the message
Re: How to set-up two 'defaultrouter' IPs?
Phillip Smith (mailing list) [EMAIL PROTECTED] writes: What I'd like to do is this... right now my NIC answers 212.12.12.212 (for instance) externally and that's the address I use for Apache's NameVirtualHost directives. I would also like my NIC to answer on 252.12.12.212 (second network connection) and serve the same VirtualHost directives... So, what happens is, in NS1.NAMESERVER.NET (which is on the 212 network) the A record for my box is 212.12.12.212 and, if that network should fail, the requests will be answered by NS2.NAMESERVER.NET (which is on the 252 network) and it has an A record for my box of 252.12.12.212. So, in effect, the name server's availability actually directs the traffic to the available network connection. Does that make sense? Sure. What you want isn't two default routers, because at any given time there's only one way you want to route this traffic. What you really want is to change default router when the outside world sees one as down. A little tricky, because the system itself might not see main network as problematic, even though the rest of the Internet does. To Unsubscribe: send mail to [EMAIL PROTECTED] with unsubscribe freebsd-questions in the body of the message
Re: How to set-up two 'defaultrouter' IPs?
On Wed, 29 Jan 2003, Lowell Gilbert wrote: Does that make sense? Sure. What you want isn't two default routers, because at any given time there's only one way you want to route this traffic. What you really want is to change default router when the outside world sees one as down. A little tricky, because the system itself might not see main network as problematic, even though the rest of the Internet does. Not multiple default routers, but multiple default routes, in this case two, with different metrics to control failover. This is easy to do on some systems (Cisco and Solaris), not so on others. Don't know about FreeBSD, but I'll take a look later if the question hasn't been answered already. KeS To Unsubscribe: send mail to [EMAIL PROTECTED] with unsubscribe freebsd-questions in the body of the message
Re: How to set-up two 'defaultrouter' IPs?
On Wednesday, Jan 29, 2003, at 08:24 US/Central, Phillip Smith (mailing list) wrote: See reply below... To create a somewhat redundant network connection, my friend has connected to business level ADSL connections at his home (32 IPs each). So, he has two routers, on two different networks (ATT/UUNET) and what he's doing is multi-homing his NIC cards and via some interesting DNS set-up, theoretically, there is some network redundancy or failover or something. Anyway, here's the question... how would I set-up two 'defaultrouter' IPs in my rc.conf? Is that were I would do such a thing? I'd like to have the same scenario that he's building with a multi-homed NIC and two IPs per VirtualHost directive. I guess there are actually many steps to accomplish this (as I now start to think about it) but I'm wondering how to set-up the networking piece first. Many thanks in advance, Two truly default routes is not really sensical. You generally play games based on source address, TCP port, or something like that, and make sure that they NAT separately. [It has to involve NAT, because for networks that small, you can't get routes distributed widely enough to do true multihoming.] So the answer depends on exactly what hack you want to do. What I'd like to do is this... right now my NIC answers 212.12.12.212 (for instance) externally and that's the address I use for Apache's NameVirtualHost directives. I would also like my NIC to answer on 252.12.12.212 (second network connection) and serve the same VirtualHost directives... So, what happens is, in NS1.NAMESERVER.NET (which is on the 212 network) the A record for my box is 212.12.12.212 and, if that network should fail, the requests will be answered by NS2.NAMESERVER.NET (which is on the 252 network) and it has an A record for my box of 252.12.12.212. So, in effect, the name server's availability actually directs the traffic to the available network connection. Does that make sense? I have been running a setup like this for years, and it doesn't require cooperation from the ISP's. Just a little ipfw trickery... Pick your 'primary' ISP, and set your machine up like normal, with default route etc. Now alias an IP from the second network onto the same network interface. Now your machine will respond to requests under each address, but the responses will go through the default route. To fix that you can use just a sprinkle of ipfw magic: If the source address of an outbound package equals the second (aliased) IP, then use the 'fwd' command to redirect the package to the second router. Example: Let's assume you picked 212.12.12.212 as the primary address, and 252.12.12.212 as the second (aliased) IP (both /28 networks, gw is the last number in the second routers IP address, change as needed). Now these ipfw rules will do the trick: add 1000 allow all from 212.12.12.212 to any add 1010 allow all from any to 252.12.12.212/28 add 1020 allow all from any to 212.12.12.212/28 add 1030 fwd 252.12.12.gw all from 252.12.12.212 to any The first rule short-circuits all packets coming from the 'primary' IP and sends them out unmodified. The second and third rule make sure that the packets that stay within your networks are not modified. The fourth rule takes the remaining packages coming from the 'secondary' IP and forwards them to the 'secondary' gateway. This works fine with anything I tried. However for connections coming from your network (eg your workstation) the default gateway is still honored. So when I am working and my primary connection goes down, I fire up a little script that reverses the roles of the primary and secondary ISP. But again that is only required for connections originating inside your network. All connections coming from the outside will do the right thing with above trickery. Another note: Having the 2 name servers on the different networks return just the IP of 'their' nettwork is probably a bad idea. The name/IP pairs will be cached on other users systems (even if TTL is set low). It is probably better to simply return both IP's. Any decent (mail/http/whatever) client will try the second IP when the first times out. But that has the side effect of spreading connections over both ISPs, which may or may not be desired. Gerd To Unsubscribe: send mail to [EMAIL PROTECTED] with unsubscribe freebsd-questions in the body of the message
Re: How to set-up two 'defaultrouter' IPs?
Phillip Smith (mailing list) [EMAIL PROTECTED] writes: To create a somewhat redundant network connection, my friend has connected to business level ADSL connections at his home (32 IPs each). So, he has two routers, on two different networks (ATT/UUNET) and what he's doing is multi-homing his NIC cards and via some interesting DNS set-up, theoretically, there is some network redundancy or failover or something. Anyway, here's the question... how would I set-up two 'defaultrouter' IPs in my rc.conf? Is that were I would do such a thing? I'd like to have the same scenario that he's building with a multi-homed NIC and two IPs per VirtualHost directive. I guess there are actually many steps to accomplish this (as I now start to think about it) but I'm wondering how to set-up the networking piece first. Many thanks in advance, Two truly default routes is not really sensical. You generally play games based on source address, TCP port, or something like that, and make sure that they NAT separately. [It has to involve NAT, because for networks that small, you can't get routes distributed widely enough to do true multihoming.] So the answer depends on exactly what hack you want to do. To Unsubscribe: send mail to [EMAIL PROTECTED] with unsubscribe freebsd-questions in the body of the message
