Cisco ISR 1841

The ISR is the only IPv6 network device in Barcelona. It acts as a router between the WiFi VLAN and a tunnel to the IPv6 Internet.

Its configuration is rather simple and is described below.

Enable IPv6

And include some basic security.

ipv6 icmp error-interval 10
ipv6 unicast-routing
no ipv6 source-route
ipv6 cef

Configured IPv6 tunnel

interface Tunnel100
 description IPv6 Tunnel to Tata Communications
 no ip address
 ipv6 address 2001:5A0:1A00::52/126
 ipv6 mtu 1480
 tunnel source ...
 tunnel destination ...
 tunnel mode ipv6ip
 tunnel path-mtu-discovery

Local interface

The ISR will send periodic Router Advertisement (as well as respond to Router Solicitation). It also sends other-config so that Windows Vista (and others) can initiate a stateless DHCP request to get DNS & NTP information. The MTU is advertised as 1480 to take into account the tunnel header.

interface FastEthernet ...
 description Interface towards Networkers Conference
 no ip address
 speed auto
 full-duplex
 ipv6 address 2A01:3E0:3::1/64
 ipv6 mtu 1480
 ipv6 nd prefix 2A01:3E0:3::/64 600 300
 ipv6 nd other-config-flag
 ipv6 nd router-preference High
 ipv6 nd ra lifetime 30
 ipv6 nd ra interval 10
 ipv6 verify unicast reverse-path

IPv6 Routing

The easiest way: an IPv6 static route through the tunnel + a local catch up for wrongly addressed packets.

ipv6 route 2A01:3E0:3::/48 Null0
ipv6 route ::/0 2001:5A0:1A00::51

Netflow v9 for IPv6

flow exporter FLOW-EXPORTER-1
 destination ...
 source ...
 port ...
 template data timeout 1

flow monitor FLOW-MONITOR-1-OUT
 record netflow ipv6 original-output
 exporter FLOW-EXPORTER-1
 statistics packet protocol
 statistics packet size

flow monitor FLOW-MONITOR-1-IN
 record netflow ipv6 original-input
 exporter FLOW-EXPORTER-1
 statistics packet protocol
 statistics packet size

interface FastEthernet ....
 ipv6 flow monitor FLOW-MONITOR-1-IN input
 ipv6 flow monitor FLOW-MONITOR-1-OUT output  

interface Tunnel100 
 ipv6 flow monitor FLOW-MONITOR-1-IN input
 ipv6 flow monitor FLOW-MONITOR-1-OUT output

SNMP Access over IPv6

snmp-server community ...:-)... RO ipv6 SNMP_ACCESS

ipv6 access-list SNMP_ACCESS
 remark SNMP ACL
 remark Local access in Barcelona
 permit ipv6 any 2a01:3e0:3::/64

DHCPv6 Server

ipv6 dhcp pool Networkers2009
 address prefix 2A01:3E0:3::/64
 dns-server 2A01:3E0:3::2
 domain-name cisconetworkers6.com
 sntp address 2A01:3E0:3::2

interface FastEthernet...
 ipv6 dhcp server Networkers2009 rapid-commit allow-hint

Syslog & DNS

ip name-server 2A01:3E0:3::2
logging host ipv6 2A01:3E0:3::2
ntp server 2a01:3e0:3::2