cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
27620
Views
5
Helpful
5
Replies

ospf port

CSCO11749402
Level 1
Level 1

hi everyone

I have silly question

u know EIGRP use RTP for relaiablity but what about OSPF , which protocol ospf uses for reliability?

5 Replies 5

Jon Marshall
Hall of Fame
Hall of Fame

CSCO11749402 wrote:

hi everyone

I have silly question

u know EIGRP use RTP for relaiablity but what about OSPF , which protocol ospf uses for reliability?

OSPF uses an port at the IP layer ie. port 89 so it does not use TCP for reliable delivery. So to ensure reliable delivery of LSAs OSPF uses implicit and explicit acknowledgement of transmitted LSAs. Implicit means a duplicate LSA is sent back to the orginating router. Explicit simply means an LSA acknowledgement is sent.

Jon

tnx dude

sorry jon

but I have another question

u said port 89 ? where we use this port in the layer 4 of osi model ?

what is tcp port number  in osi in layer 4 ?

Hello,

It is an IP protocol, not a Layer 4 port. Similar to TCP/UDP, OSPF uses a

protocol type defined as 89.

Here is a excerpt from Wiki:

OSPF does not use a TCP/IP transport protocol (UDP, TCP), but is

encapsulated directly in IP datagrams with protocol number 89. This is in

contrast to other routing protocols, such as the Routing Information

Protocol (RIP), or the Border Gateway Protocol (BGP). OSPF handles its own

error detection and correction functions.

Hope this helps.

Regards,

NT

oh ya tnx

but I'm confused between ip protocol and osi layer do u have any resource for me ?

Getting Started

Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community: