Cisco 6500 - Catalyst Series 10 Gigabit EN Interface Module Expansion, Configuration Manual, Page: 198 / 742

10-6
Catalyst 6500 Series Switch and Cisco 7600 Series Router Firewall Services Module Configuration Guide using ASDM
OL-20748-01
Chapter 10 Configuring IPv6
Configuring IPv6 Neighbor Discovery
•
protocol —Specifies the traffic being controlled by the access list entry. This can be the name ( ip ,
tcp , or udp ) or number (1-254) of an IP protocol. Alternatively, you can specify a protocol object
group using object-group grp_id .
• source and destination —Specifies the source or destination of the traffic. The source or destination
can be an IPv6 prefix, in the format prefix / length , to indicate a range of addresses, the keyword any,
to specify any address , or a specific host designated by host
host_ipv6_addr.
•
src_port and dst_port —The source and destination port (or service) argument. Enter an operator ( lt
for less than, gt for greater than, eq for equal to, neq for not equal to, or range for an inclusive
range) followed by a space and a port number (or two port numbers separated by a space for the
range keyword).
• icmp_type —Specifies the ICMP message type being filtered by the access rule. The value can be a
valid ICMP type number (from 0 to 155) or one of the ICMP type literals as shown in Appendix E,
“Addresses, Protocols, and Ports” . Alternatively, you can specify an ICMP object group using
object-group id .
Step 2
To apply the access list to an interface, enter the following command:
hostname(config)# access-group access_list_name { in | out } interface if_name
See the “Example 4: IPv6 Configuration Example” section on page B-13 for an example IPv6 access list.
Configuring IPv6 Neighbor Discovery
The IPv6 neighbor discovery process uses ICMPv6 messages and solicited-node multicast addresses to
determine the link-layer address of a neighbor on the same network (local link), verify the reachability
of a neighbor, and keep track of neighboring routers.
This section contains the following topics:
•
Configuring Neighbor Solicitation Messages, page 10-6
• Configuring Router Advertisement Messages, page 10-8
Configuring Neighbor Solicitation Messages
Neighbor solicitation messages (ICMPv6 Type 135) are sent on the local link by nodes attempting to
discover the link-layer addresses of other nodes on the local link. The neighbor solicitation message is
sent to the solicited-node multicast address.The source address in the neighbor solicitation message is
the IPv6 address of the node sending the neighbor solicitation message. The neighbor solicitation
message also includes the link-layer address of the source node.
After receiving a neighbor solicitation message, the destination node replies by sending a neighbor
advertisement message (ICPMv6 Type 136) on the local link. The source address in the neighbor
advertisement message is the IPv6 address of the node sending the neighbor advertisement message; the
destination address is the IPv6 address of the node that sent the neighbor solicitation message. The data
portion of the neighbor advertisement message includes the link-layer address of the node sending the
neighbor advertisement message.
After the source node receives the neighbor advertisement, the source node and destination node can
communicate.
Figure 10-1 shows the neighbor solicitation and response process.