NLRI What is this?

Can anyone simple explain what this.

Currently from what I'm reading it exactly the same as a prefix......
192.168.1.0/24 = NLRI

If BGP advertises a network/prefix it's called NLRI, correct?

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Comments

networker050184

Network Layer Reachability Information. For just an IPv4 prefix that is about all there is to it. When you get into subsequent address families more info is carried.

FrankGuthrie

networker050184 wrote: »

Network Layer Reachability Information. For just an IPv4 prefix that is about all there is to it. When you get into subsequent address families more info is carried.

Ok, so my conclusion is correct?

NLRI = Prefix =>192.168.0.0/24?

Dieg0M

Like Networker said, that is just for IPv4. For vpnv4 for example, you will have label stack information carried in the NLRI field.

fredrikjj

Dieg0M wrote: »

Like Networker said, that is just for IPv4. For vpnv4 for example, you will have label stack information carried in the NLRI field.

I'm going to nitpick a bit here, don't get mad

What you are saying is true, but they're not really the same fields. In IPv4, the prefix/prefix-length is carried in the NLRI field:

(BGP update)

But, when you use a non-IPv4 NLRI, that's carried inside the Path Attribute field in the multiprotocol reachability attribute. The RFC calls it MP_REACH_NLRI (Type Code 14). Inside this attribute there's a different NLRI field than the "main" IPv4 NLRI field.

FrankGuthrie

Thanx guys