Users Guide

Table Of Contents
IPv6 destination unreachable
By default, when no matching entry for an IPv6 route is found in the IPv6 routing table, a packet drops and no error message
is sent. You can enable the capability to send an IPv6 destination unreachable error message to the source without
dropping the packet.
Enable IPv6 unreachable destination messaging
OS10(config)# interface ethernet 1/1/8
OS10(conf-if-eth1/1/8)# ipv6 unreachables
IPv6 hop-by-hop options
A hop-by-hop header extension in an IPv6 packet contains options that are processed by all IPv6 routers in the packet's path.
By default, hop-by-hop header options in an IPv6 packet do not process locally. To enable local processing of IPv6 hop-by-hop
options on an interface, use the ipv6 hop-by-hop command.
Enable IPv6 hop-by-hop options forwarding
OS10(config)# interface ethernet 1/1/8
OS10(conf-if-eth1/1/8)# ipv6 hop-by-hop
IPv6 Routing Header Type 0
Routing header is an extension header that is defined in RFC 2460 for IPv6. A source uses routing header to list one or more
intermediate nodes that a packet takes to reach its destination. Routing header is modeled similar to the IPv4 Loose Source and
Route IP options. It consists of routing type field, which further identifies the extension.
The Type 0 routing header extension (RH0) is used for listing the addresses of the intermediate nodes for the packet to take
to reach its destination. RH0 can also be used to perform denial of service attacks, bypassing filtering and firewall devices, and
other kinds of security attacks. Therefore, this extension is depreciated in RFC 5095. OS10 switches are compliant with RFC
5095. However, you can use the following command to drop all IPv6 packets with RH0 in case there is any noncompliant router
or node in the network:
[no] ipv6 routing-header-type0 deny fast-path [slow-path]
Restrictions and Limitations
IPv6 RH0 packets are not dropped in hardware (fast-path) in the following scenarios:
IPv6 RH0 packets for which Routing Header is present beyond first 128 bytes of the packet.
IPv6 RH0 packets matching a Policy Based Routing (PBR) entry is routed and not dropped.
IPv6 RH0 packets with hop-by-hop header are not dropped when the ipv6 hop-by-hop CLI configuration is present. This
restriction can be overcome using the slow-path parameter.
View IPv6 information
To view IPv6 configuration information, use the show ipv6 route command. To view IPv6 address information, use the
show address ipv6 command.
View IPv6 connected information
OS10# show ipv6 route connected
Codes: C - connected
S - static
B - BGP, IN - internal BGP, EX - external BGP
O - OSPF,IA - OSPF inter area, N1 - OSPF NSSA external type 1,
N2 - OSPF NSSA external type 2, E1 - OSPF external type 1,
E2 - OSPF external type 2, > - non-active route
Gateway of last resort is not set
Destination Gateway Dist/Metric Last Change
910
Layer 3