network in bgp

I have a layer 3 core and it currently has BGP running on it. I need to add another network  in BGP, 192168.1.0/24. Will it work if I just do "network 192168.1.0 mask" in the BGP process? I read somewhere that BGP will advertise if it has a route to that network. My BGP knowledge is limited so any tips will be greatly appreciated. Thanks

router bgp 65001
 no synchronization
 network mask
 redistribute connected
 neighbor  remote-as 65010
 no auto-summary

ip route 
ip route 250

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AkinsdNetwork AdministratorCommented:
You will need to add the neighbor first with the neighbor command

BGP works differently from other routing protocols
leblancAccountingAuthor Commented:
the existing config already has the  neighbor  remote-as 65010 command
BGP requires that you have an internal route (OSPF, EIGRP, static, connected, whatever) for the same network with the same mask before it will advertise it. You don't need to redistribute it, but it needs to verify the advertised route against the normal routing table.
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leblancAccountingAuthor Commented:
so what do I need to make it work.
Well, if you type "show ip route" is the route you want to advertise in BGP in your routing table?
AkinsdNetwork AdministratorCommented:
Split Horizon and/or synchronization rules.

The BGP synchronization rule states that if an AS provides transit service to another AS, BGP should not advertise a route until all of the routers within the AS have learned about the route via an IGP. Disabling this negates the need to already have a route from an internal routing protocol.

You've disabled that already, so that leaves us with the split horizon rule

BGP split horizon rule state that : When a BGP speaker receives an UPDATE message from an internal peer, the receiving BGP speaker shall not re-distribute the routing information contained in that UPDATE message to other internal peers.."

Verify that the condition does not exist.

There's a lot to BGP and a diagram and more show commands would be necessary to diagnose the problem.

There are other things to look for also.
show ip bgp
show ip bgp summary
Let's start with a more basic question: Are you asking why it isn't working, or are you asking what you need to do to make it work? Because you do need to add that network statement if you want to advertise it out. And the above is correct, if you have no-summary on then you can just add the network statement. But keep in mind that if you don't actually have a route to the network you're advertising, it won't do you any good! The main benefit of no-summary is that you can keep advertising the route even if the internal path goes down.
leblancAccountingAuthor Commented:
"But keep in mind that if you don't actually have a route to the network you're advertising, it won't do you any good! " That is what I am trying to understand.
My Cisco core layer 3 switch has  a SVI 192168.1.1/24. All the access switches have a default route pointed to that SVI. So where is the route that I need to have BGP advertised? Thx
If you're advertising to the internet, you can't be advertising 192.168.x.x You have to advertise whatever public addressing you own. Just saying...

Now if you are using BGP in your own network between your own routers, no problem. I asked you earlier to type "show ip route" to see if the route you want to advertise is in the routing table of the BGP router. If it's a connected LAN as you suggest, it will be in the routing table and you shouldn't have any problem.
AkinsdNetwork AdministratorCommented:
Do you have BGP arrangement with your ISP?.
Configuring BGP on your network requires you to have a neighbor relationship with your ISP using an AS number provided to you. They will assign one to you and give you theirs. Just creating your own AS does no good. BGP AS numbers has to be unique.

Disregard the above if your BGP setup is for lab purpose.
Follow BGP rules and you'll be fine.

Did you check the items I mentioned in the last post? If you haven't, I'll strongly recommend you start from there and save yourself some headache

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leblancAccountingAuthor Commented:
This is a MPLS circuit w/ BGP peering. My configuration is correct. I believe they screwed up in their MPLS cloud because it is working now after they made a change in their routing table. I have a question though. What does redistribute connect do? Why do you need it? Thanks
AkinsdNetwork AdministratorCommented:
That redistributes connected routes into BGP. It's easier and cleaner compared to redistributing routes from routing protocols. Since it is not a good practice to publish internal routes into bgp, you'll have to use route maps in conjunction with BGP redistribution to filter out unwanted routes.

For more information about this, see the pdf document in the link below
I would disagree with the above comment. Redistribute connected has nothing at all to do with redistributing from routing protocols. It adds routes from physically connected interfaces, whereas a routing protocol adds routes learned from other routers. But you have to be careful because again, you don't want to advertise private networks to your ISP. That's why unless you have a bunch of different networks to advertise, it's better to use network statements- you have more control.
leblancAccountingAuthor Commented:
"...adds routes from physically connected interfaces" I completely agree with you. So if my internal subnets are and and I advertise "network and network" under my BGP process and my SVIs are and, I do not need to redistribute connected. Correct?
It doesn't matter if the network in your routing table is connected, static route, EIGRP, etc. That's why I keep referring back to the "show ip route" command. If the route shows up there and the network statement matches the route exactly, it will work.

If you have a lot of connected routes to advertise AND you want to advertise them all, then you could use "redistribute connected" as a shortcut. You can use a distribute-list in conjunction with "redistribute connected" (or any other redistribution) to deny or permit only certain routes to show up into BGP.

Incidentally, the no sync command discussed earlier doesn't affect any of this in your case. That has to do with advertising routes learned via iBGP.
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