Choose Policies→Routing→Community from the NFM-P main menu. The Routing Policy - Communities form opens.

Click Create or choose a policy and click Properties. The Routing Policy - Community, Global Policy form opens.

Configure the required parameters on the General tab.

Perform one of the following:

Note: You must create at least one Community Expression or Community Member for this policy type.

1. To create a Community Expression, go to Step 5 .

2. To create a Community Member, go to Step 6 .

Click on the Community Expression tab and click Create. The Community Expression, Site (Create) form opens.

1. Configure the Exact Match parameter as required.

2. Enter a string in the Community Expression text field. Use Boolean operators to define the policy actions between different values. Valid expression operators include: AND, OR, and NOT. For example, if you enter the following string:

   target:5:1000 OR target:9:10

   then the policy matches a route that has either target. Or if you enter:

   2:2 AND 200:200

   then the policy only matches a route that has both targets.

   The Boolean operators can also be used with parentheses and combined into a more complex expression, such as:

   (8:8 AND NOT 9:9) OR (7:7)

   In this case, the policy matches a route which contains the regular expression for target 8:8 with the exception of target 9:9, or just target 7:7 alone.

   Any community, extended community, large community, or well-known community can be part of the Community Expression. Valid values for the Community Expression’s components include:

   • Community Values, such as 100:100

   • Extended Community Values, such as target:1:1, origin 1:1, target:1.1.1.1:1, or origin 1.1.1.1:1. On supporting NEs, flowspec-set:<ext-asnum>:<group-id>, and flowspec-set-trans:<ext-asnum>:<group-id> are configurable; see the NE documentation.

   • Regular expressions for origins, such as origin:.*&.*

   • Regular expressions for communities, such as 100|200:100|200

   • Regular expressions for extended community values, for example, Extended Community Bandwidth:<as-number>:<value in Mbps> to specify link bandwidth

   • Large Community Values (on supporting NEs; see the NE documentation)

   • Well-known Community values

   Note:

   When constructing a Community Expression, Community IDs must be limited to 75 characters maximum, and regular expressions must be limited to 72 characters maximum. The entire Community Expression must be limited to 900 characters maximum.

   Community Expressions are supported on the 7750 SR, 7750 SR-c12, 7750 SR-12E, and 7450 ESS. IOM3 is required, in chassis mode B, C, or D.

3. Save your changes. The Routing Policy - Communities form reappears. Go to Step 7 .

Note: 7x50 NEs support non-matching lists for regular expressions.

Click on the Community Members tab and click Create. The Community Member, Site (Create) form opens.

1. Configure the Community Member parameter.

   For extended communities, use the generic format of ext:<value1>:<value2> or ext:<regex1>&<regex2>, where:

   • ext is a keyword similar to target and origin

   • <value1> if 4 hex digits, then <value2> can have 1-12 hex digits

   • <value1> if 2 hex digits, then <value2> can have 1-14 hex digits

   • <regex1> is a regular expression that can match a pattern of 4 hex digits representing the first 2 bytes of the extended community

   • <regex2> is a regular expression that can match a pattern of 1-12 hex digits representing the last 6 bytes of the extended community

   Use of the <regex> attributes can provide flexibility for removing multiple extended communities from a BGP route.

   Note:

   If you are configuring an origin validation state extended community for BGP SIDR, configure ext:xx[yy]:value, where ext indicates an extended community and value indicates the new origin validation state, from 0 to 299.

   The ext format has following restrictions:

   • <value1> must have the value 4300, specifying a non-transitive opaque extended community

   • <value2> can have values 0, 1, or 2, corresponding to the three possible origin valid states

   If you are configuring a link bandwidth extended community, then configure the Community Member as: bandwidth:<as-number>:<value in Mbps>

   If you are creating a flowspec-set or flowspec-set-trans community member that will be used in an embedded filter, set the group-ID value to the same value configured for the Group ID parameter in To configure an embedding filter with embedded filter policies. The format for flowspec-set and flowspec-set-trans values is <AS-number>:<group-ID>.

2. Save your changes. The Routing Policy - Communities form reappears. Go to Step 7 .

Save your changes and close the form. See To release and distribute a policy to release and distribute the policy to NEs.

Note: A routing policy is discovered as local edit only. To synchronize a routing policy with all NEs, you must change the distribution mode of the routing policy to sync with the global policy. See To change the distribution mode of a policy to change the distribution mode of a routing policy.

End of steps