| Protocolo | Distancia administrativa |
|---|---|
| Directamente conectados | 0 |
| Ruta estática | 1 |
| Ruta EIGRP sumarizada | 5 |
| BGP externa | 20 |
| EIGRP interna | 90 |
| IGRP | 100 |
| OSPF | 110 |
| IS-IS | 115 |
| RIP | 120 |
| EGP | 140 |
| ODR | 160 |
| EIGRP externa | 170 |
| BGP interna | 200 |
| Desconocida | 255 |
Hasta el 2007, los números AS estaban definidos como un entero de 16-bits, lo que permite un número máximo de 65.536.
IANA controla los números AS. Y estos son asignados de la siguiente forma:
| Number | Description |
|---|---|
| 0 | reserved. |
| 1-64.495 | public AS numbers. |
| 64.496 – 64.511 | reserved to use in documentation. |
| 64.512 – 65.534 | private AS numbers. |
| 65.535 | reserved. |
Desde el 2007 los ASN son de 32-bits.
| Number | Bits | Description |
|---|---|---|
| 0 | 16 | Reserved for RPKI unallocated space invalidation[11] |
| 1 - 23455 | 16 | Public ASNs. |
| 23456 | 16 | Reserved for AS Pool Transition. |
| 23457 - 64495 | 16 | Public ASNs. |
| 64496 - 64511 | 16 | Reserved for use in documentation/sample code. |
| 64512 - 65534 | 16 | Reserved for private use. |
| 65535 | 16 | Reserved. |
| 65536 - 65551 | 32 | Reserved for use in documentation and sample code. |
| 65552 - 131071 | 32 | Reserved. |
| 131072 - 4199999999 | 32 | Public 32-bit ASNs. |
| 4200000000 - 4294967294 | 32 | Reserved for private use. |
| 4294967295 | 32 | Reserved. |
Para activar el routing con multi-homing. Hay que activar el forwarding:
# echo 1 > /proc/sys/net/ipv4/ip_forwarding
Para que en caso de reinicio del linux quede activado, modificaremos el fichero /etc/sysctl.conf añadiendo la siguiente línea.
# vi /etc/sysctl.conf
net.ipv4.ip_forward = 1
Y con el siguiente cambio aplicaremos el cambio:
# sysctl -p