7.8.1.0 - Force10 Networks

The Payload Length limit of 2 bytes requires that the maximum packet payload be 64 KB. However, the
Jumbogram option type Extension header supports larger packet sizes when required.
Next Header (8 bits)
The Next Header field identifies the next header’s type. If an Extension header is used, this field contains
the type of Extension header (Table 33 ). If the next header is a TCP or UDP header, the value in this field
is the same as for IPv4. The Extension header is located between the IP header and the TCP or UDP
header.
Table 33 Next Header field values
Value Description
0 Hop-by Hop option header following
4 IPv4
6 TCP
8 Exterior Gateway Protocol (EGP)
41 IPv6
43 Routing header
44 Fragmentation header
50 Encrypted Security
51 Authentication header
59 No Next Header
60 Destinations option header
Note: This is not a comprehensive table of Next Header field values. Refer to the Internet
Assigned Numbers Authority (IANA) web page http://www.iana.org/assignments/protocol-numbers
for a complete and current listing.
Hop Limit (8 bits)
The Hop Limit field shows the number of hops remaining for packet processing. In IPv4, this is known as
the Time to Live (TTL) field and uses seconds rather than hops.
Each time the packet moves through a forwarding router, this field decrements by 1. If a router receives a
packet with a Hop Limit of 1, it decrements it to 0 (zero). The router discards the packet and sends an
ICMPv6 message back to the sending router indicating that the Hop Limit was exceeded in transit.
Source Address (128 bits)
The Source Address field contains the IP address for the packet originator.
FTOS Configuration Guide, version 7.8.1.0 411