Multicast filtering must be done per session (host) for IPoE and PPPoE. There are two types of filters that are supported:
IGMP filters on access ingress. Those filters control the flow of IGMP messages between the host and the BNG. They are applied with the import statement in the igmp-policy. The same filters are used for multicast-redirection policy:
For IPv4:
configure
subscr-mgmt
igmp-policy <name>
import <policy-name>
For IPv6:
configure
subscr-mgmt
mld-policy <name>
import <policy-name>
An example of the filter definition is shown below:
configure
router
policy-options
begin
prefix-list <pref-name>
prefix <pref-definition>
policy-statement <name>
entry 1
from
group-address <pref-name>
source-address <ip>
protocol igmp
exit
action accept
exit
exit
default-action reject
Regular traffic filters where control multicast traffic flow can be controlled in both directions (ingress/egress). This is supported through ip-filters under the SLA profile.
For IPv6 specifically, up to 15 import policies can be applied to the subscriber IPv6 host. Each of the import policies can be configured as an IPTV package. Depending on the IPTV package the subscriber ordered, a list of import policies is applied at authentication.
At authentication, the first 14 import policies are applied either through LUDB or RADIUS using a list of VSAs. These 14 import policies are not read in any particular order and to make the list deterministic as a black list or a white list, the import policy inside the MLD policy must be configured. The import policy inside the MLD policy is always applied as the last policy which determines whether the list of 14 policies is a white list or a black list. For example, to make the list of 15 import policies a white list, the first 14 policies should have action configured as accept and the last import policy inside the MLD policy should have default action configured as reject. For a black list, the first 14 policies should have action configured as reject and the last import policy inside the MLD policy should have default action configured as accept. It is recommended to configure the MLD import policy with a default action without an import list which is used to determine if the list is a black or white list. If the last import policy is overridden, it changes the MLD policy which in turn overrides the subscriber profile.
It is possible to make a mixed black and white list, where the general rule is that the import policy inside the MLD policy is always the last to be applied to the subscriber.
The list of MLD import policies can be overridden either through RADIUS CoA or through the tools>perform>subscriber-management>coa command. There are two VSAs for overriding the list of import policies. The first VSA, Alc-Mld-Import-Policy, is used to completely override the first 14 MLD policies. A RADIUS CoA can contain up to 14 VSAs to override the existing list. Because of limitations with the length of a CLI command, up to five VSAs can be passed to override the existing list when using the tools command. The second VSA, Alc-Mld-Import-Policy-Modif, allows the addition or subtraction of a single MLD import policy. To add an import policy to the existing list, use a prefix of ‛a:’ and to remove an import policy, use a prefix of ‛s:’, for example, ‛a:sport-pack1-hd’ or ‛s:movie-pack1-hd’. Multiple import policies can be added or removed within a single CoA by using multiple VSAs. Up to five import policies can be added or removed using a single CoA. The last import policy inside the MLD policy can be overridden using the subscriber profile.
If a subscriber is not associated with an MLD policy, the import policies applied either at authentication or overridden in mid-session are always stored while the subscriber is online. The import policy does not take effect as long as the subscriber is not associated with an MLD policy. However, as soon as the subscriber is associated with an MLD policy, the list of import policies stored is instantly applied.