The route-map manager supports four distinct types of route-maps:
A named route-map consists of a set of permit or deny entries. Entries are sequenced by unique sequence numbers per named route-map. A route-map can contain multiple route-map sequences. Route-map entries are not unlike the permit and deny statements in an ACL with one very important exception: unlike the ACL, all route-map entries must be successful for this route-map‘s action to occur.
Each route-map sequence may contain one or more match and set clauses. A match clause contains the criteria that determines whether the permit or deny action for this entry should be taken. All route-map entries for a given sequence must be successful for a route-map action to occur. If multiple sequences are configured, the first one that matches all entries will “pass” and return the set actions for that sequence. If a sequence does not pass, the next sequence is processed until a sequence in which all entries match is found. If no entries match for all sequences, then the route-map is not used.
A set clause defines the action for this route-map. Depending on the route-map type and permit/deny setting of the route-map sequence, zero or more set clauses are supported per route-map sequence.
For policy based route-maps, if a match clause is configured, a match of the packet‘s source IP address against the contents of the specified ACL is required. A set entry specifies up to 5 next hop IP addresses for the forwarding of this packet. On the S- and K-Series, multiple set clauses can be configured.
Note
On the 7100-Series, Policy Route-maps are limited to a single ACL with a single permit sequence (permit 10) in the match clause. The default, if none, is explicitly selected.Policy based route-maps must be associated with an interface before route-mapping occurs. When assigning a route-map to an interface, the next hop load-policy behavior, which configures the algorithm used to select the next hop, and prioritization, which determines whether the priority based or routing table next hop is used, or whether the packet is dropped.
Default next hops can be configured on the S- and K-Series and are only used when:
If both criteria are true, the next hop will be chosen from the default-next hop IP address list, using the configured load-policy setting.
If the next hop of a policy IP address match belongs to a different VRF, you can set the next hop VRF to perform the route lookup.
The route-map probe feature provides for the configuration of an ICMP probe to monitor next hops.
For redistribution route-maps, if a match clause is configured, a match of the packet source IP address against either a specified VLAN or the contents of one or more specified ALCs is required. A configured set entry specifies a route tag, metric, metric increment or decrement, or metric type to be used for redistribution by the ACLs matched in this route-map.
Redistribution route-maps, with a set entry specifying a route tag, must be assigned to the redistribute command within the OSPF router configuration command mode, for redistribution based upon this route-map to occur.
For OSPF filter route-maps, if a match clause is configured, a match on a deny route-map will deny the matched route from being installed into the OSPF route table based upon IP network address, next hop, source router-ID, outbound interface, OSPF tag, metric cost, or route-type.
OSPF filter route-maps must be assigned to the distribution-list route-map in command within OSPF configuration command mode for OSPF route table filtering to occur.
For BGP permit route-maps, all match clauses within a sequence must match for set clauses to be performed. For BGP deny route-maps, all match clauses within a sequence must match for the packet to be dropped. There is an exception to the all match clauses rule: in the case of multiple match prefix entries, only a single prefix entry needs to match. BGP route-maps support match clauses for:
BGP route-maps support set clauses for:
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