EGP message types
The various exterior gateway protocol (EGP) message types are defined here.
| Item | Description |
|---|---|
| Neighbor Acquisition Request | Used by exterior gateways to request to become neighbors of each other. |
| Neighbor Acquisition Reply | Used by exterior gateways to accept the request to become neighbors. |
| Neighbor Acquisition Refusal | Used by exterior gateways to deny the request to become neighbors.
The refusal message includes reasons for refusal, such as out of table
space. |
| Neighbor Cease | Used by exterior gateways to cease the neighbor relationship. The
cease message includes reasons for ceasing, such as going down. |
| Neighbor Cease Acknowledgment | Used by exterior gateways to acknowledge the request to cease the neighbor relationship. |
| Neighbor Hello | Used by exterior gateways to determine connectivity. A gateway issues
a Hello message and another gateway issues an I Heard
You message. |
| I Heard You | Used by exterior gateways to reply to a Hello message.
The I Heard You message includes the access of the answering
gateway and, if the gateway is unreachable, a reason for lack of access, such
as You are unreachable because of problems with my network interface. |
| NR Poll | Used by exterior gateways to query neighbor gateways about their ability to reach other gateways. |
| Network Reachability | Used by exterior gateways to answer the NR Poll message.
For each gateway in the message, the Network Reachability message
contains information on the addresses that gateway can reach through its neighbors. |
| EGP Error | Used by exterior gateways to respond to EGP messages that contain bad checksums or have fields containing incorrect values. |
TCP/IP implements the EGP protocol in the gated server command and does not provide an API to this protocol.