Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

what's the hello packet of the cdp protocol filled in?

all ip addresses of the interfaces on the router enabled are filled in the hello packet of the cdp protocol ,otherwise the odr protocol can't run normally.

i think so !

Everyone's tags (1)
1 REPLY

Re: what's the hello packet of the cdp protocol filled in?

all ip addresses of
the interfaces on the router enabled are filled in the hello packet of
the cdp protocol ,otherwise the odr protocol can't run normally.

i think so !

Hi,

CDP is a media and protocol independent protocol that runs on all Cisco-manufactured equipment including routers, bridges, access and communication servers, and switches.  Using CDP, you can view information about all the Cisco devices directly attached to the switch.  In addition, CDP detects native VLAN and port duplex mismatches.

Protocol-Hello-Allows other protocols to piggyback their Hello packets onto Cisco Discovery Protocol.If you sniff the cdp apcket you can see protocol hello in cdp packet which has the following field in the frame

VLAN Trunking Protocol (VTP) management domain-Names the management domain

Native VLAN-Indicates the number of the native VLAN

Full or half duplex-Indicates if the interface is operating in half or full duplex

Appliance VLAN-Indicates the voice VLAN

Trigger-Offers ability to cause the remote end to immediately send a Cisco Discovery Protocol packet

Power-Adds capability to negotiate power

Extended trust and class of service (CoS)-Offers ability to specify whether the PC port of the phone is trusted and if not, what to mark the Layer 2 packet CoS bits coming in from the PC port.

Sysname-Indicates fully qualified domain name (FQDN) of the device per RFC 1907

sysObjectID-Gives object identifier (OID) per RFC 1907

Management address-Indicates IP addresses for which the device accepts Simple Network Management Protocol (SNMP) messages

Physical location-Gives a string representing the physical location of the devices

External port ID-Identifies the physical fiber

Power requested-Specifies how much power is being requested

Power available-Specifies how much power is available

Port unidirectional mode-Specifies that traffic on this port is one way only

Hope that clear out your query !!

Ganesh.H

698
Views
0
Helpful
1
Replies
CreatePlease login to create content