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How to redistribute between BGP and possibily EIGRP?

m-abooali
Level 4
Level 4

hi,

I made a few posting but i belive I was not clear on the problem and that was due to lack of information. here it is and I need some input please:

we are going to buil a new infrastrature using 4x 6506 and 4 x 6509 Cisco switches L2/L3.

two of which stay at one site and the other two if which will go to another site. both sites will be linked through dark fiber as transit from aprovider.

I have been thinking about BGP and Route Reflector design but I don't know what would be the relation between the two 6506s at each site and the two 6509 sitting behind them?

they want to run EIGRP internally (internal LAN behind the 6506s), here i have gotten confused of how I can link these devices together given the fact that I have not seen redistribution between BGP and EIGRP?

I know the BGP configuration, I know the eBGP and iBGP relations but EIGRP and BGP, I don't know to tackle that?

Please see if you can help me clear these things in my mind and move forwad with the design.

Regards,

Mike

1 Accepted Solution

Accepted Solutions

Also, given the fact that the two 6509 switches at LAN Site 2 are L2 swithces, I wonder how should I go about creating a L3 single VLAN Interface for our PVLANs and their (the switches 6509) relation to the EIGRP interfaces?

Are those switches Layer2 switches because they lack a routing module, or they are Layer2 switches because ip routing isn't enabled?

As for PVLANs, please refer to this document:

http://www.cisco.com/en/US/docs/switches/lan/catalyst6500/ios/12.2SXF/native/configuration/guide/pvlans.html

According to the diagram, perhaps the design requires for routed connections between switches and run a dynamic routing protocol between them, see this article for more information:

http://www.cisco.com/application/pdf/en/us/guest/netsol/ns431/c649/ccmigration_09186a00808f6c34.pdf

This has beena great learning experience for me and thanks for sharing yoyr experties with me. I am sure that this posting will be usefull to a lot of people.

It would be more useful if you rated the posts :)

HTH,

__

Edison.

View solution in original post

15 Replies 15

Edison Ortiz
Hall of Fame
Hall of Fame

What's the requirement for running 2 routing protocols ?

Can you just run EIGRP?

The only reason I would run BGP between the locations is if they were managed by different companies and you wanted to avoid if they make changes in their IGP (EIGRP) to affect your IGP.

If both locations are run by the same IT department, run EIGRP - much simpler.

HTH,

__

Edison.

This is a very good point but here what I have and what I have been told to do.

two locations, separated by Dark Fiber, and

two 6506s in each location to serve as border routers with also SUP engine to support one VLAN Interface for PVLANS.

two 6509 at each location to serve as core switches.

the two 6506 at one location is going to talk to the upsteam providers using BGP and then this traffic has to travel over the dark fiber to this location hitting or terminating on teh second 2x6506 at this location and tghen down to two 6509 again. the two 6509 are L2 corer switches for customers connectivity.

Now, I was thinking to use BGP and Route reflector to eliminate the need for EIGRP or OSPF if possible?

here is where I have gotten confused on what IGP i need to use? and relation of this IGP to my BGP border routers?

I have been pressed for time sine two network engineers have taken over this and quited later only after one week concerning about time! i am determine to do this and achieve something but I do have my limitation and for this limitation I have written to you guys to see if with your help I can get my mind clear about relation between BGP at Bordeer taking to two Service providers and IGP to the internal LAN?

so, there are two service providers here an dtghe two sites are separated by dark fiber. at one of th elocations, the two 6506 will talk BGP to thos eproviders.

I cannot see th erelation between the BGP and IGP in my mind and cannot visualize it!?

can I only use BGP (route reflector) and not need and IGP such as EIGRP or OSPF? or I am missing something?

Please advise.

Regards,

Mike

the two 6506 at one location is going to talk to the upsteam providers using BGP and then this traffic has to travel over the dark fiber to this location hitting or terminating on teh second 2x6506 at this location and tghen down to two 6509 again. the two 6509 are L2 corer switches for customers connectivity.

Hi Mike,

Ok, so this dark fiber is a Layer3 connection to a provider, got it.

This BGP will most likely be eBGP as providers typically don't share their AS.

With that in mind, eBGP does not need route-reflector.

I recommend running an IGP (OSPF or EIGRP) in the LAN at each location and use BGP just for the WAN connectivity to the provider.

A route reflector configuration is only needed if you have multiple iBGP speaking devices and they aren't fully meshed. I don't see the need for that based on what you've told us.

You can also run a seamless IGP between locations with a GRE tunnel between the 6500 switches. This design avoids any redistribution between BGP and an IGP of your choice.

Will the provider carry your internal routes or this is a MPLS dark fiber?

__

Edison.

Hi Edison,

yes, this dark fiber is a L3 connection and I need to have the two 6506 talk BGP with two different providers. you are right about the eBGP and only the WAN Connections and in fact this makes it easier. we will be receiving Partial Routes from the providers - this is what has been discussed between them for the past 6 months and deicided for and now I have arrived into the picture!

I did bring up the GRE tunnel but they want to have EIGRP in LAN locations and redistribute (may face loop and other admin overheads). but this is how they want to do it.

what I don't understand is how to make this redistibution happen using the BGP redistribution command but i don't know where I need to run the eigrp?

this has made me confused!

so, if we want to only run EIGRP at the LAN locations, would be on the 6506s i assumes?

what would the relation be to 6509s, the core switches with PVLANS?

if you could please help me see this in my mind then I can configure the devices for BGP and EIGRP.

I have not run Two Routing protocols together before and this fact has confused me!

also, if I put the SUP engine 720 in 6506s then how can I relate to the PVLANS as far as the 6509s are concern?

I really appreciate your input and thoughts on this.

Regards,

Mike.

I did bring up the GRE tunnel but they want to have EIGRP in LAN locations and redistribute (may face loop and other admin overheads). but this is how they want to do it.

Under what scenario may you see a loop ?

Redistribution from BGP to an IGP is done in a lot of networks without a loop.

You need to find out if the provider is going to carry your internal routes, if they are not - you need a GRE tunnel.

For the 'routing protocol' configuration, you will configure BGP and EIGRP on the same 6500 box and perform redistribution from BGP to EIGRP and from EIGRP to BGP.

Private Vlans are layer2 segmentation so secondary Vlans would connect to the primary Vlan. It should work the way it's working now, I don't see the need to bringing this up for the WAN connection. One thing though, Private Vlans won't extend over the dark fiber.

if you could please help me see this in my mind then I can configure the devices for BGP and EIGRP.

router bgp 65000

neighbor x.x.x.x remote-as 1

redistribute eigrp

no auto-summary

router eigrp 1

network x.x.x.x y.y.y.y

redistribute bgp 65000 metric 1 1 1 1 1

no auto-summary

I have not run Two Routing protocols together before and this fact has confused me!

It's not bad at all. Make sure to enable EIGRP on the LAN interfaces and BGP will do its thing via the WAN interface.

It seems this project is a bit over your head, can you ask for help from a local consulting company?

I recommend understanding all the pieces before deploying in a live network.

Thanks Edison.

this information is really helpful to me. I have attched a network drawing to make it easier to see the intention.

I have told them that I need help and they are thinking about it but for now, I am alone.

I will ask the providers about carrying my internal routes/'traffic but shouldn't redistribution from eigrp to BGP do the trick?

Please let me kno wif the rawing has provided more information that i need to be aware of.

so, to recap, there should be no problem redistributing eigrp to bgp and vice vers on the 6500 (respected Interfaces), correct?

one more thing? these devices are RJ21 interfaces/blades, is there any special aconsideration for RJ21 that i need to be aware of on top of the RJ21 carring 12 Ethernet ports?

I will keep in touch in case they tell me to bring in help.

Regards,

Masood

Thanks for posting the diagram, it does help.

The situation is a little different from the way you explained.

The BGP is only for the internet and the dark fiber connection is a physical connection.

Treat that connection as if the switches were in the same building so whatever protocols you are running now, should remain the same.

The diagram stipulates to run EIGRP inside both LANs, it shouldn't be a problem.

BGP will be enabled on the 2 top-most switches. On this scenario, you don't need to redistribute from EIGRP to BGP and from BGP to EIGRP.

Under EIGRP, you can announce a default route back to the internal devices and then in turn, you will need to NAT your internal IP subnet out to the internet, therefore the internet does not need route reachability back to you (no redistribution needed).

hello again, I really appreaciate your thoughts on this as it has already helped shaping my thoughts given that I have only been here for 5 days now.

I have attached another diagram showing the actual MUX that will lit the fiber and yes I can treat this switches at the other site as if they are on a different floor, just an extention to the first LAN at Physical layer, layer 1.

they are not running any daynamic Routing Protocols at this time on this old network but they want to have EIGRP on both LANs and BGP at the two WAN Routers/Switches.

I have worked with BGP and VLANS/PVLANs, etc. but I have not worked on EIGRP in real word scenario and now under pressure with very little time i have to make it happen.

so, for EIGRP, I start on the same switch, i.e. the WAN router that I ahve BGP up to the provider except that I use a different Interface of course! and work my way down to other devices.

This way, on my two WAN routers i will have:

router bgp AS#

and

router eigrp #

correct?

and this # for eigrp doesn't have to be the BGP AS#, I assume ans based on the classes I have taken it can be any number?

I will also, keep the 6509s as is for core L2 swithces taking care of the PVLANs but one question remains here, creating one VLAN interface to have all PVLANs under it, has to be a L3 VLAN and that interface must be a L3 Interface/routable? how would I route these VLANs over the network when I have EIGRP running?

I am sorry, I think I asked too many questions but its a real world learning experience and can be usefull to many other on the Netpro so i don't hesitate to ask questions that i have confusion on how to approach them. I really hope you don't mind that>

Please see the new drawing attached.

Regards,

Mike

Hi Edison,

in the diagram that I posted last, please ignore the two 6509s in LAN Site 1. This this the lan site where we have the WAN connections routers located as well but we havev two MUXs to lit the fiber at bothe locations, each capable of 2 Wavelenghts and has two gigi ethernet ports. we can go with one MUX too but they have it in place and I am trying to use them.

I will post the corrected diagram in one or two hours from now.

Regads,

Mike

Hi Edison,

attach please find the new design diagram without the two 6509s in LAN site 1 but I have included the MUXs that are used to lit the dark fiber, connecting to the 6506s. I have documentation for those MUX and how to be configured and connected so no prblem there.

It seems that the design has gotten somehow easire given the two 6509s are out of the picture now.

you see, I got my inofrmaton from them piece of piece on a daily bases and din't have the whole thing at once which created a lot of confusion for me and i provided some worng information to you and i am sorry for that.

now, this is the final diagram and i have highlighted the point of question in "Yellow".

Also, given the fact that the two 6509 switches at LAN Site 2 are L2 swithces, I wonder how should I go about creating a L3 single VLAN Interface for our PVLANs and their (the switches 6509) relation to the EIGRP interfaces?

Please see if you can help me clear this confusion and I will start testing this plan in two days- testing first and then cutting over if al works the way thet are intended to. hopefully.

This has beena great learning experience for me and thanks for sharing yoyr experties with me. I am sure that this posting will be usefull to a lot of people.

I don't know if I mentioned this or not? this is for a Web Hosting Company and thats way the PVLANs.

Regards,

Mike

Also, given the fact that the two 6509 switches at LAN Site 2 are L2 swithces, I wonder how should I go about creating a L3 single VLAN Interface for our PVLANs and their (the switches 6509) relation to the EIGRP interfaces?

Are those switches Layer2 switches because they lack a routing module, or they are Layer2 switches because ip routing isn't enabled?

As for PVLANs, please refer to this document:

http://www.cisco.com/en/US/docs/switches/lan/catalyst6500/ios/12.2SXF/native/configuration/guide/pvlans.html

According to the diagram, perhaps the design requires for routed connections between switches and run a dynamic routing protocol between them, see this article for more information:

http://www.cisco.com/application/pdf/en/us/guest/netsol/ns431/c649/ccmigration_09186a00808f6c34.pdf

This has beena great learning experience for me and thanks for sharing yoyr experties with me. I am sure that this posting will be usefull to a lot of people.

It would be more useful if you rated the posts :)

HTH,

__

Edison.

Thanks very muck and I do rate the post for sure and infact right now.

I will go throgh the documentation now but my question was infact on the issue you broght up, IP routing isn't enable? and sure, they are only L2 and I was wondering how the connection if these swithces will be with the two 6506s at the edge of lan site 2 right before hitting the dark Fiber?

Once again, I appreciate your help.

Regards,

Mike

You can inspect the installed hardware on those boxes for a Supervisor with MSFC.

If you have a MSFC, all it takes is enabling ip routing if it's disabled.

If they are truly L2, then you are only able to trunk the Vlans and have the other switches perform the routing for those Vlans.

__

Edison.

I will do that as soon as power them up today. I think they are purley L2 based on what I avev been told but I will check.

I think, as you put it:

I need to trunk the vlans and have the 6506s to do the routing for the said vlans.

The document on EIGRP is very helpful, I wasn't able to find something like this on my own since I did searched alot for the past week but this one is swesome! Thank you.

can I write back to you next week if I encounter problems that I am not able to resolve? our Smartnet contract is still in the progress but not yet approved. I am waiting on the vendor to complete that process. I can refer to these postings if its alright with you?

Regards,

Mike

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