EIGRP in the real world

jude56g

I have been working in networking in various capacities for the last 9 years and not once have I seen EIGRP (or RIP for that matter) in the wild. Anyone out there use these protocols regularly??

Monkerz

Funny you ask. Monday is my last day with my current employer, and just yesterday I had to explain to "the outsourcee(s)" why we are using BGP, OSPF, RIP and two different instances of EIGRP. So yes, this company is using it, but not in the way I would like.

Forsaken_GA

jude56g wrote: »

I have been working in networking in various capacities for the last 9 years and not once have I seen EIGRP (or RIP for that matter) in the wild. Anyone out there use these protocols regularly??

Most experienced network engineers will shy away from proprietary protocols when the network is composed of gear from multiple vendors. If you're vendor locked to just Cisco gear, there's no problem with EIGRP, it's a very robust and fairly easy protocol.

However, when you've got a mix of vendor gear, if you want to use EIGRP with your Cisco gear, you can, but in order for routes to be shared with other vendors gear, you have to do route redistribution. This adds points of complexity and points of failure to the network, which is generally not a good idea to do on purpose. It's one thing to start a network with EIGRP because you have all Cisco gear, and then you grow and scale and start tossing in things like Junipers. In those cases, redesigning your IGP to run OSPF or ISIS or RIP everywhere is generally not going to be worth it, and then you'd introduce the redistribution points.

Designing a network from the ground up with redistribution points? You're insane, a glutton for punishment, or really hate the people who have to work with or succeed you.

shodown

EIGRP is used quite often it depends on what environment you are in. When I do small designs 20-30 sites over MPLS I usually use EIGRP at the HQ or large branch site for the LAN. Works really well just turn it on. I've seen it on larger wan segments and its usually broken into smaller segments then paired with BGP to route between the AS'es. EIGRP can scale to a pretty decent size. I would however choose OSPF/BGP over EIGRP/BGP.

shodown

Forsaken_GA wrote: »

Designing a network from the ground up with redistribution points? You're insane, a glutton for punishment, or really hate the people who have to work with or succeed you.

You would be shocked how often I see networks with Redistribution in the Design. Sometimes there is a vald reason for it(IE the LAN group is actually another activity and you don't want to run routing protocols so they send you statics and you redistribute them)

Other times, Its just because someone who's been there longer than you makes all the rules and thats how they roll cause its all they know.

nerdydad

I currently work for a VERY large corporation, and they use EIGRP exclusively. I was pretty shocked when I started, they also had the entire network go down once because of auto-summarization in EIGRP. Of course they use BGP as well, but the IGP is EIGRP.

Forsaken_GA

shodown wrote: »

You would be shocked how often I see networks with Redistribution in the Design. Sometimes there is a vald reason for it(IE the LAN group is actually another activity and you don't want to run routing protocols so they send you statics and you redistribute them)

Actually, I should probably clarify my stance - designing redistribution between routing protocols is insane, et al. Redistributing static and connected routes, along with liberal use of GRE tunnels, are the glue that holds many a network together That I really don't have a problem with. But designing EIGRP zones and OSPF zones and redistributing between them on purpose when you could have just used OSPF on both? Drives me batshit insane.

Other times, Its just because someone who's been there longer than you makes all the rules and thats how they roll cause its all they know.

Yup. It's like Gary Donahue says... networks design is influence by three things : politics, money, and the right way to do it - in that order. It's unfortunate when the only design justification used (or needed) is based on institutional inertia or the statement 'because I said so'

shodown

Don't even get me started on the politics and the right way to do it. We always have plenty of time to do it over instead of enough time to do it right the 1st time.

Todd Burrell

If I had a dollar for how many times I have been told "we've always done it this way" I could retire. Politics is the main problem at most jobs I've had - the actual technical work is usually the easy part. And I always love how most technical decisions seem to be made by someone with little if any technical knowledge.

DragonNOA1

I've only worked with EIGRP, so think how I feel. OSPF is a big confusing mess in comparison. I work at a hospital, the other two hospitals that are partnered with us run EIGRP, and another hospital that we just brought into our organization runs EIGRP also. I could ask, does anyone run OSPF?

Roguetadhg

Don't forget that EIGRP is cisco proprietary. Juniper, i've heard, puts out good equipment as well.

SteveO86

Working for an MSP I've got my hands in many different networks. The IGP is either EIGRP or OSPF and most of the larger ones run OSPF due to it being vendor nuetral. Only a handful of large ones with money spend are all Cisco EIGRP. Haven't seen RIP in production at all yet, as you would expect.

OSPF is all fun and games till someone puts 500+ WAN links of all different types in the same area...

Roguetadhg

SteveO86 wrote: »

OSPF is all fun and games till someone puts 500+ WAN links of all different types in the same area...

Sweet use of summarization!

Forsaken_GA

SteveO86 wrote: »

OSPF is all fun and games till someone puts 500+ WAN links of all different types in the same area...

That's really not that big of a deal, OSPF can scale pretty well. The only real issue is if you have links that flap all the time, causing SPF runs... then it's a big deal.

Now, if all 500 of those WAN links are redistributing a full BGP into OSPF.... sure, then you've got some fun times ahead.

ColbyG

I see mostly EIGRP.

lrb

I see mostly OSPF.

Funnily enough, a few years back I actually saw a client whose senior architect had designed the network from the ground up with several virtual links

SteveO86

Forsaken_GA wrote: »

That's really not that big of a deal, OSPF can scale pretty well. The only real issue is if you have links that flap all the time, causing SPF runs... then it's a big deal.

Yea, there is a bit of link flapping Some of the WAN link rely on DSL and EVDO (IPSec running over it) not the most stable technology out there. They should be in their own little area by themselves...

Forsaken_GA

SteveO86 wrote: »

Yea, there is a bit of link flapping Some of the WAN link rely on DSL and EVDO (IPSec running over it) not the most stable technology out there. They should be in their own little area by themselves...

Yeah, having those kinds of links in your backbone area is non intelligent design hehe. If possible those should be stubbed out, but isolated to their own area and summarized into the backbone if at all possible. But I suspect you already knew that, and it's that politics thing at work again

shodown

SteveO86 wrote: »

Yea, there is a bit of link flapping Some of the WAN link rely on DSL and EVDO (IPSec running over it) not the most stable technology out there. They should be in their own little area by themselves...

This is asking for a disaster if more than too many links go down at one time and SPF starts to continuously calculate and the network never converges. True story. When I was working a WAN job they were doing there usual late night maintenance. When a Large fiber line cut overseas they lost a few links to core sites(one of the overseas sites had to be in area 0.0.0.0) and combined with the maintenance they were doing SPF kept running over and over, so the Whole US was kinda shut down from the combined maintenance and fiber cut. One the problem was Isolated they actually had so call someone overseas to go shut down the router OSPF recognized the link being down, recalculated SPF and everything was good.

jude56g

For what its worth, I just found out yesterday that we are moving to iBGP as our IGP in the majority of our network. I will get a lot of hands on with that so hopefully that will help when I get to ROUTE.