ping 224.0.0.5 "Hello" on OSPF.

yrwins

Hi,
I have a quick question?
the hello for OSPF is 224.0.0.5. so if I ping 224.0.0.5 is the hello.
can you ping hello on any router protocol?

OctalDump

Depending on how the equipment and network is set up, if you ping the multicast address you will get responses from all devices listening to that address. A ping is not the same as a Hello, though.

Pings use ICMP packets, but OSPF messages (including the Hello message) use their own packet format - IP protocol number 89.

The Hello message packet includes a whole bunch of information, specific to OSPF.

Other routing protocols behave in different ways. BGP is encapsulated in TCP packets, EIGRP uses RTP (IP protocol 8, RIP uses UDP. BGP uses unicast addressing, EIGRP uses multicast, RIPv1 uses broadcast, RIPv2 and RIPng use multicast.

yrwins

HMMMMM.
I Know the Ping is not the same as a Hello .
on my lab, if I ping the 204.0.0.5 "Multicast address" of OSPF I get all the router a ICMP echo Replies.


EIGRP multicast address is 224.0.0.10
OSPF and EIGRP are protocol 89 and 88, respectively though and not port numbers I think. Protocol numbers are included in the header like TCP (protocol 6) and UDP (protocol 17), Port 88 is Kerberos but protocol 88 is EIGRP if that makes sense.

that address is for OSPF routers that are not DR or BDR routers. so what happen when multicast Address of the DR and BDR. can you ping any Multicast Adress to get all router? and compare with you router table. !!!!

I'm really lost.

james43026

A port and a protocol # aren't the same thing. A protocol number in network communication just identifies what protocol a frame / packet / segment should be passed to next AKA what protocol is encapsulated. So for a OSPF packet, the frame will have a header field called ethertype, which will have code that referes to IPv4 or IPv6 most commonly, and then in the IP packet you will have a protocol field, a code of 89 in this field indicates that OSPF will be handling the data encapsulated by the IP packet. Pinging 224.0.0.5 or 224.0.0.6 does not mean that OSPF is working, it mearly means that a device has been configured to listen and respond to a specific multicast group.

A port is associated with a process / service that is running on a device.