User`s guide
166
Routing modes
The TransPort has 2 routing modes available, these are:
TransPort routing mode
This is the original routing method and may be seen on existing installations.
CIDR routing mode
Now enabled by default on new TransPort routers.
The CLI command to switch between the 2 modes is:
ip 0 cidr [off|on]
TransPort routing mode
CIDR routing is disabled
When the TransPort receives an IP packet to route, the routing table is used to decide
through which interface to send the packet.
Usually the destination IP address of the IP packet is compared with the IP Address and
Mask of each entry in the routing table in index order regardless of the order in the routing
table or length of mask.
There may be more than one match and in this case the index number of the route is taken
into account. The index number is simply the route number in the config, Static Route 0 or
1 is index 0 or 1
Static routes are checked first, then dynamic routes, then default routes.
CLI command:
ip 0 cidr off
CIDR routing mode
CIDR routing is enabled
When the TransPort receives an IP packet to route, the routing table is used to decide
through which interface to send the packet.
Usually the destination IP address of the IP packet is compared with the IP Address and
Mask of each entry in the routing table.
There may be more than one match and in this case the most specific route is used to route
the packet. Ie, a matching /24 route is used before a matching /16 route.
If multiple routes match the destination and have the same prefix length, the index number
of the routes in the routing table is used to determine the route.
CLI command:
ip 0 cidr on
Route Metrics
Route Metric settings can be set to override the order in which the routes are searched.
Routes with lower metric numbers will always be used in preference to routes with higher
metric numbers even if the routes with higher metric numbers appear first in the routing
table.
Route metrics can be configured by means of the route parameters:
Connected Metric
Disconnected Metric