# multicast addresses in corosync

**URL:** <https://forums.suse.com/t/multicast-addresses-in-corosync/35625>\
**Category:** General\
**Created:** [June 12, 2021, 9:17am UTC](https://forums.suse.com/t/multicast-addresses-in-corosync/35625 "2021-06-12T09:17:50Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Ortwin](https://avatars.discourse-cdn.com/v4/letter/o/ea666f/32.png) [@Ortwin](https://forums.suse.com/u/Ortwin)\
**Post date:** [June 12, 2021, 9:17am UTC](https://forums.suse.com/t/multicast-addresses-in-corosync/35625/1 "2021-06-12T09:17:50Z")

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According to the lesson, corosync can use unicast and multicast addresses, with multicast making cluster expansions more easy, but bringing the problem of all clusters seeing the nodes of all clusters - not only their own.  
Would it be possible to change the used multicast address iin corosync, so each cluster would use it’s own mutlicast group?

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**Author:** ![Academy\_Instructor](https://avatars.discourse-cdn.com/v4/letter/a/9d8465/32.png) [@Academy\_Instructor](https://forums.suse.com/u/Academy_Instructor)\
**Post date:** [June 14, 2021, 7:03pm UTC](https://forums.suse.com/t/multicast-addresses-in-corosync/35625/2 "2021-06-14T19:03:27Z")

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Hello, the following is from the technical documentation for HA:  
When using multicast, the same bindnetaddr , mcastaddr , and mcastport will be used for all cluster nodes. All nodes in the cluster will know each other by using the same multicast address. For different clusters, use different multicast addresses.  
I hope this helps.