isatap automatic-tunnelling intrasite overview and example config

13.12 2019 | by massimiliano

---

ISATAP Intra Site Automatic Tunnel Addressing Protocol   – Connecting between host-to-host, router-to-host, host-to-router   – Use underlying IPv4 network […]

https://www.ingegnerianetworking.com/wp-content/uploads/2019/12/isatap-example-3a0.png

ISATAP Intra Site Automatic Tunnel Addressing Protocol

 

– Connecting between host-to-host, router-to-host, host-to-router

 

– Use underlying IPv4 network as NBMA cloud

 

– Tunnel operates per packet-basis to encapsulation (different by 6to4)

 

– ISATAP interface identifier is (on the middle part of address): 0000:5EFE

 

– Tunnel mode: ipv6ip isatap

 

– The destinations address are automatically determined

 

Format address ISATAP

 

[ 64-bit link-local or global unicast prefix ] : 0000:5EFE: [ ipv4 address isatap link ]

 

 

Esempio:

 

IPv6 prefix = 2001:0db8:0abc:0def::/64

 

IPv4 tunnel destination = 172.20.20.1 (converted in hex = ac14:1401)

 

ISATAP address = 2001:0db8:0abc:0def:0000:5e5f:ac14:1401

 

 

 

CONFIG EXAMPLE:

 

ISATAP ROUTER

 

ipv6 unicast-routing

!

interface Loopback0

 ip address  1.1.1.1  255.255.255.255

!

interface Tunnel 1

 no ip address

 no ip redirects

 ipv6 address 2001:DB8:CAFE:65::/64 eui-64   << Any /64 IPv6 address  will work >>>

 no ipv6 nd ra suppress     <<IPv6 ra is suppressed by default on tunnel. Need to re-enable for client auto-configuration >

 tunnel source Loopback0

 tunnel mode ipv6ip isatap

 

 

 

ISATAP CLIENT ROUTER

 

interface ethernet0

 ip address  20.0.0.2 255.255.255.0

!

interface Tunnel 1

 no ip address

 ipv6 address autoconfig

 ipv6 enable

 tunnel mode ipv6ip

 tunnel source ethernet0

 tunnel destination 1.1.1.1