Static Routes and Administrative Distance [7:72495]
I accidentally deleted the posting about this but I wanted to make a point. It's been said that a static route has an AD of 1 unless it points directly out an interface, in which case it has an AD of 0. Sasa just mentioned that this has been discussed in the past and is a myth. However, I'd like to agree with the 'myth'. A directly connected route has an AD of 0. If you create a static route pointing directly out an interface, that route will show up as directly connected in the routing table, and would therefore have an AD of 0. In fact, if you look at a static route you'll see the usual [AD/metric] listed as [1/0]. However, if you look at a static route pointing out an interface this is missing. This is because the router treats that route as if it were directly connected to the interface. If I'm wrong about this--and I certainly might be--please let me know where my reasoning is incorrect. Regards, John Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=72495&t=72495 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: Static Routes and Administrative Distance [7:72495]
John, The behavior changed with the IOS releases. Newer IOS releases with static routes pointing to an interface will have an administrative distance of 1, not 0. Older versions will have an administrative distance of 0. Unfortunately I do not know the exact release in which the behavior changed. The term "myth" is too strong and it's possible that the people that haven't worked with the older IOSs do not realize that this behavior was once different. This is the output from one of my routers running 12.2(15)T: Lab#show ip route 10.1.1.0 Routing entry for 10.1.1.0/24 Known via "static", distance 1, metric 0 (connected) Routing Descriptor Blocks: * directly connected, via Serial0 Route metric is 0, traffic share count is 1 As far as I know, certification study materials still expect you to think that a static route to an interface has an AD of 0. - Tom John Neiberger wrote: > I accidentally deleted the posting about this but I wanted to make a point. > It's been said that a static route has an AD of 1 unless it points directly > out an interface, in which case it has an AD of 0. Sasa just mentioned that > this has been discussed in the past and is a myth. However, I'd like to > agree with the 'myth'. > > A directly connected route has an AD of 0. If you create a static route > pointing directly out an interface, that route will show up as directly > connected in the routing table, and would therefore have an AD of 0. In > fact, if you look at a static route you'll see the usual [AD/metric] listed > as [1/0]. However, if you look at a static route pointing out an interface > this is missing. This is because the router treats that route as if it were > directly connected to the interface. > > If I'm wrong about this--and I certainly might be--please let me know where > my reasoning is incorrect. > > Regards, > John Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=72501&t=72495 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: Static Routes and Administrative Distance [7:72495]
John Neiberger 7/17/03 12:12:42 PM >>> >I accidentally deleted the posting about this but I wanted to make a point. >It's been said that a static route has an AD of 1 unless it points directly >out an interface, in which case it has an AD of 0. Sasa just mentioned that >this has been discussed in the past and is a myth. However, I'd like to >agree with the 'myth'. > >A directly connected route has an AD of 0. If you create a static route >pointing directly out an interface, that route will show up as directly >connected in the routing table, and would therefore have an AD of 0. In >fact, if you look at a static route you'll see the usual [AD/metric] listed >as [1/0]. However, if you look at a static route pointing out an interface >this is missing. This is because the router treats that route as if it were >directly connected to the interface. > >If I'm wrong about this--and I certainly might be--please let me know where >my reasoning is incorrect. > >Regards, >John Nevermind, I've answered my own question by testing. A static route definitely has an AD of 1 regardless of the destination. If you simply do a "show ip route static" you won't see an administrative distance listed; it will show as directly connected. However, if you look at a specific static route, like 'show ip route 10.1.1.1', no matter which destination you used it will look like this: Router#sho ip route 20.1.1.1 Routing entry for 20.1.1.1/32 Known via "static", distance 1, metric 0 (connected) Redistributing via eigrp 1 Routing Descriptor Blocks: * 172.16.10.75 Route metric is 0, traffic share count is 1 directly connected, via Ethernet0/2 Route metric is 0, traffic share count is 1 This output is caused by having both flavors of static route in the routing table at the same time. If the AD of one of them was actually zero it would be the only one listed. In this case, they both have an AD of 1. Regards, John Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=72500&t=72495 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: Static Routes and Administrative Distance [7:72495]
I am skeptical, Tom. Someone, I think it was Howard, researched this as far back as 9.x releases without finding the AD=0 behavior. I can't support this as I couldn't find it in the archives and I have not tried it myself. But, in order to prove that AD=0 never existed one would have to test all releases, a task that is probably impossible without a museum of hardware. But I think the burden of proof has to lie with the pro-AD=0 faction given the history on this issue. Tom Martin wrote: > > John, > > The behavior changed with the IOS releases. Newer IOS releases > with > static routes pointing to an interface will have an > administrative > distance of 1, not 0. Older versions will have an > administrative > distance of 0. Unfortunately I do not know the exact release in > which > the behavior changed. Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=72502&t=72495 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
