Is there ever a good time to use RIP?

malcybood

Hi,

Almost everything I've read in preparing for my CCNA study says that you should try to avoid using RIP or IGRP and opt for OSPF or EIGRP as your IGP routing protocol.

BT designed our ADSL WAN network (remote sites) which runs over ATM and after looking at the config of 3 of the routers I have to install next week on ADSL sites I noticed that the LAN network address for the remote site and the WAN network address are advertised using RIP version 2.

We have 1 data centre (350 users) and approximately 250 ADSL sites (up to 20 users each, with some with ISDN backup), and 14 other regional offices (up to 80 users each) that run a BT 2MB IP Clear Cellstream network (x.21). The IP Clear offices use Cisco 2500/2600 routers and the ADSL sites use a mix of these smaller 1841s and 1700s.

I'm trying to get more into the network management side of things and we don't currently have any Cisco certified engineers other than myself (when i get it) due to the network being outsourced and us managing them/what they do.........

so my questions after all of this is why would this ATM network have been designed using RIP and is it feasible for me to mention the constraints of this protocol to the Technoloy manager and suggest alternatives such as EIGRP or OSPF (bearing in mind it would be a project in itself)? Is RIP still as bandwidth and CPU intensive in an ATM network of 250 odd sites or does it work differently?

The Tech Manager is taking me along to his next meeting with Cisco in May so I am looking to express my interest as much as I can and show that I'm being proactive in spotting this type of thing, but this isn't something I'm looking to mention "for the hell of it" ....it's a genuine thing I noticed in regard to the way we currently have things confiugred, and I'm trying to help improve our systems performance, based on my CCNA study in this case.

Thanks for any replies

Malc

seraphus

Are you sure the RIPv2 sites aren't redistributed?

I know RIPv2 doesn't run over that whole network....

EdTheLad

Maybe the engineer didn't know eigrp and ospf well enough so he took the easy option with Rip.The funny thing is i did the same thing about eight years ago, i setup an atm core, i needed ip connectivity at all remote sites for management traffic so i implemented this with the cisco routers i was given using rip.It worked fine, for a while! but when management started dropping out randomly we needed to change to ospf.
That was the first glimpse of Cisco i had but i didn't really know what i was doing.
Anyway Rip on an atm network can cause you problem depending on how you implement it, if you have a hub and spoke topology the router has to send the same updates out every pcv so the hub can get congested with updates.
Rip is easy to setup and manage and in some networks it can perform better than Ospf, for distance vector protocols my preference is definitely with eigrp.So if i were you i would ask why rip and not eigrp.

malcybood

seraphus wrote:

Are you sure the RIPv2 sites aren't redistributed?

I know RIPv2 doesn't run over that whole network....

I'm not sure, as it's all outsourced they control the ATM setup side of the network. We just install the routers and do some debugging etc in order to et the site up and running at the moment.

Thanks though it's something I'll remember to ask when I put the question forward.

malcybood

EdTheLad wrote:

Maybe the engineer didn't know eigrp and ospf well enough so he took the easy option with Rip.The funny thing is i did the same thing about eight years ago, i setup an atm core, i needed ip connectivity at all remote sites for management traffic so i implemented this with the cisco routers i was given using rip.It worked fine, for a while! but when management started dropping out randomly we needed to change to ospf.
That was the first glimpse of Cisco i had but i didn't really know what i was doing.
Anyway Rip on an atm network can cause you problem depending on how you implement it, if you have a hub and spoke topology the router has to send the same updates out every pcv so the hub can get congested with updates.
Rip is easy to setup and manage and in some networks it can perform better than Ospf, for distance vector protocols my preference is definitely with eigrp.So if i were you i would ask why rip and not eigrp.

Cheers Ed,

So in theory how would an EIGRP implementation work in the environment I described? I know you don't know the exact topoloy but as I say in theory. I'm not quite sure what IP protocol the cellstream sites use but would they need to be changed to EIGRP on the same autonomous system too?

Would you have 250 sites on the same autonomous system i.e. eigrp 20? Bearing in mind that we would still use providers ATM network.....hope this makes sense and you et what I mean.....any more info you need let me know

One last thing to mention is would the routing protocol have any type of impact on the performance on our Nortel VOIP system? Our succession server runs in Edinburgh HQ and serves all of the regional offices with the 2MB Cellstream link on each site that has the VOIP phone system. May be irrelevant but something thouht I'd ask anyway......

cheers

EdTheLad

Eigrp over a hub and spoke just sends periodic hellos rather than full routing tables.You could even setup stub eigrp which means limited updates.It's not really appropriate for me to say whats right for your topology as i dont know what it is and what other variables are in play.
The best you can do for now is ask wny rip was implemented, there might be a good reason regarding some equipment just supports rip etc.

malcybood

EdTheLad wrote:

Eigrp over a hub and spoke just sends periodic hellos rather than full routing tables.You could even setup stub eigrp which means limited updates.It's not really appropriate for me to say whats right for your topology as i dont know what it is and what other variables are in play.
The best you can do for now is ask wny rip was implemented, there might be a good reason regarding some equipment just supports rip etc.

cool thanks for the info

Paul Boz

Use OSPF. If you ever have to introduce non-cisco equipment and you're using EIGRP you're going to be in quite a predicament. Stick to open standard as much as possible. Cisco likes to make you think they're the only option in networking but it's not the case.

markzab

Paul Boz wrote:

Use OSPF. If you ever have to introduce non-cisco equipment and you're using EIGRP you're going to be in quite a predicament. Stick to open standard as much as possible. Cisco likes to make you think they're the only option in networking but it's not the case.

BLASPHEMY!

rossonieri#1

Paul Boz wrote:

Use OSPF. If you ever have to introduce non-cisco equipment and you're using EIGRP you're going to be in quite a predicament. Stick to open standard as much as possible. Cisco likes to make you think they're the only option in networking but it's not the case.

WELL SAID

mikej412

If someone saved a few dollars and got the cheap SOHO/Branch Office routers.... RIP may be your only option. But there is no law that says you have to live with that mistake beyond those routers.

malcybood

mikej412 wrote:

If someone saved a few dollars and got the cheap SOHO/Branch Office routers.... RIP may be your only option. But there is no law that says you have to live with that mistake beyond those routers.

I think you may have hit the nail on the head here Mike......we still have some linksys, speedtouch and draytek routers kicking about on the ADSL sites.....we changed our WAN provider last year who are now rolling Cisco routers mentioned in initial post out, as opposed to SOHO routers such as the above mentioned.

So is this maybe a good opportunity to flag this point up and can a gradual migration take place or is this the type of thing that is an "all or nothing" migration or could you have a mixed infrastructure that would work okay?

****EDIT***** just remembered some of the sites are using the Cisco SOHO routers so I see what you mean as they only appear to support RIP

http://www.cisco.com/en/US/products/hw/routers/ps4866/products_data_sheet09186a008010e5c4.html

keatron

Man I love browsing these Cisco forums. This is good stuff. I often find myself ssh'ing into my routers to take a look and compare to some of the stuff you guys discuss here. I just changed all my routers (all 4 of em..lol) to OSPF. Now I just have to get them configured properly.

dynamik

I love all the forums - even if they're not related to anything I'm working on. Each post is like a mini soap opera, and I just can't wait to see how it ends. This site has done to my productivity what WoW has done to my wife's. Plus, I don't have 14 year old boys begging me to cyber with them

jason2713

i thought igrp and eigrp you could only use cisco equipment where with ospf and rip, you can use any equipment (unless it doesnt support it)....and that would ultimately be used for these decisions...cant run igrp on non-cisco equipment

rip sends out updates every 30 seconds however its updates are small compared to ospf if im not mistaken, so if you have a lot of routers in your network, and you run ospf on them, you may have shot yourself in the foot with all those updates running around. correct me if im wrong, but in a larger network, you'd want to run RIP V2 because the updates are so much smaller, unless you are a cisco god and can break your network into areas with ospf

im new to all this, so any corrections are welcome. im taking the ccna exam on friday haha

EdTheLad

Eigrp and Igrp are proprietary which means Cisco only, Igrp has been replaced by Eigrp so it's not used anymore, Cisco have even started removing it from current ios.
Rip sends out periodic updates, OSPF doesn't, but ospf refreshes it's lsa's every 30 minutes.These LSA's are not all refreshed at the same time as each lsa has its own timer, so you don't get a big burst of update traffic every 30 minutes.In a stable network ospf is definitely a more efficient protocol, in an unstable network if you have just one area an unstable link can cause multiple database recalculations which can effect forwarding, in this case Rip would be preferred,but you can always adjust ospf settings for it to perform better in different environments.Ospfv2 has its problems, and if you check out ospfv3 for ipv6 you will see these problems have been addressed,
You don't need to be a Cisco God to break ospf into areas,its not difficult once you start to learn about it.

malcybood

jason2713 wrote:

......unless you are a cisco god and can break your network into areas with ospf

Needing to be a network god to configure an ospf network is a bit of a sweeping statement.....

As I mentioned the network design and configs are outsourced.....I'm sure if they only had people who could configure environments for RIP then they wouldn't be one of the UKs and world's main providers for outsourced networking services......

If that was the case, that they were limited to configuring RIP, then in the long term financially, we would be as well employing a team of Cisco engineers, try to become a Cisco partner and do the whole lot ourself (which may actually end up happening to be honest)

RIP may be the most suitable protocol for what we have, however the company is projected to double in size (currently 1600 users across 350 sites/offices) in the next 5 years which prompted my original question.

Paul Boz

You don't have to be a networking god to use OSPF correctly, but you do have to at least be more skillful than your average networking professional. OSPF has volumes written on it (including several RFC's).

But for the CCNA you only need to know how to set up OSPF in the zero area, which can be done by just about anyone.

malcybood

The guy at my work who project manages the network and phone system is now back from holiday so I asked a few questions.....He said that they can use RIP in an ADSL/ATM network such as ours as it is only going over a few hops to get to the core ATM network therefore the impact on the network is minimal as RIP is acting basically as a point to point link as it is setup.

I then found out from the guy at whilst he was setting up my router on his side of things that the RIP protocol out on the site is redistributed in the ATM core to OSPF which now makes sense. This is only how our ADSL sites are setup

Our IP Clear x.21 regional offices x 14 all run the VOIP phone system and use OSPF as the IGP protocol on the site router.

When I prompted the questions, do we use RIP because it is open standard and supports the old SOHO routers we still carry? and also the fact we use OSPF as it is open standard incase for example we got a couple of Juniper routers in for example and the answer was yes to both.

Ciscopimpenator

IMO RIP is not needed in this day.

The Cisco books mention that RIP was invented when memory and processing power was limited. That was one of the reasons for RIP's design, which is good, but defnitely nothing compared to OSPF. Back when RIP was designed, OSPF convergence traffic would have been overload for small bandwith networks and having neighbor tables was extra memory which wasn't available.


OSPF is the way to go! I don't want to call RIP useless, because that's not true, but in todays network there is no reason for RIP. OSPF does everything RIP does but better.

The funny thing is when configuring OSPF and RIP for basic functions OSPF is just as easy to configure. You might as well just use OSPF and skip the thought of ever using RIP.

There is really no reason to use RIP, and the same probably goes with IGRP.