Alcatel-Lucent 7750 Configuration Manual page 506

Interfaces
Description This command enables OSPF/ISIS costing of a Link Aggregation Group (LAG) based on the available
aggregated, operational bandwidth.
The path cost is dynamically calculated based on the interface bandwidth. OSPF path cost can be changed
through the interface metric or the reference bandwidth.
If dynamic cost is configured, then costing is applied based on the total number of links configured and the
cost advertised is inversely proportional to the number of links available at the time. This is provided that the
number of links that are up exceeds the configured LAG threshold value at which time the configured
threshold action determines if, and at what cost, this LAG will be advertised.
For example:
Assume a physical link in OSPF has a cost associated with it of 100, and the LAG consists of four phys-
ical links. The cost associated with the logical link is 25. If one link fails then the cost would automati-
cally be adjusted to 33.
If dynamic cost is not configured and OSPF autocost is configured, then costing is applied based on the total
number of links configured. This cost will remain static provided the number of links that are up exceeds the
configured LAG threshold value at which time the configured threshold action determines if and at what
cost this LAG will be advertised.
If dynamic-cost is configured and OSPF autocost is not configured, the cost is determined by the cost con-
figured on the OSPF metric provided the number of links available exceeds the configured LAG threshold
value at which time the configured threshold action determines if this LAG will be advertised.
If neither dynamic-cost nor OSPF autocost are configured, the cost advertised is determined by the cost con-
figured on the OSPF metric provided the number of links available exceeds the configured LAG threshold
value at which time the configured threshold action determines if this LAG will be advertised.
The no form of this command removes dynamic costing from the LAG.
Default no dynamic-cost
encap-type
Syntax encap-type {dot1q | null | qinq}
no encap-type
Context config>lag
Description This command configures the encapsulation method used to distinguish customer traffic on a LAG. The
encapsulation type is configurable on a LAG port. The LAG port and the port member encapsulation types
must match when adding a port member.
If the encapsulation type of the LAG port is changed, the encapsulation type on all the port members will
also change. The encapsulation type can be changed on the LAG port only if there is no interface associated
with it. If the MTU is set to a non default value, it will be reset to the default value when the encap type is
changed.
The no form of this command restores the default.
Default null — All traffic on the port belongs to a single service or VLAN.
Parameters dot1q — Ingress frames carry 802.1Q tags where each tag signifies a different service.
Page 506 7750 SR Interface Configuration Guide