Wired Intelligent Edge

Hello,

I want to connect a stack of Aruba 3810M with Juniper EX4500. Is the rpvst compatible with the rstp of juniper ? or the only i can use is mstp?

Thank you

Hi,

a lot of acronyms in your message...

usually they have following meaning. Not sure on Juniper. You'll have to verify this...

rpvst: rapid per vlan spanning tree.

rstp: rapid spanning tree. not compatible with rpvst, but with mstp

mstp: multiple spanning tree. Described very short: "rapid spanning tree with multiply instances".

Assuming Juniper uses acronyms like above:

mstp is compatibnle to rstp. rpvst is not.

Regards, Jö

So, rstp and mstp would work together ?

As long as I dont have multple instances in mstp ?

Regards

Hi,

yes. They work together.

Even if you define more than one instance in mstp.

mstp switches form a region, if config name, revision and VLAN to instance mapping are configured identical.

A mstp region is seen by other switches/regions like one big rstp switch (of course only regarding the stp functionality...).

Typically mstp switches default config is like this:

1. for config name base mac address of switch is used
2. revision is 0
3. all vlans are mapped to IST instance

Bacause of "1." all mstp switches in default config have a unique mstp config name. Thus, each switch forms its own mstp region. 

In fact this default config makes mstp switches behave identical to rstp switches. E.g. no need to configure "force version rstp" or the like...

Again my disclaimer: I have no knowledge about Juniper switches...

Regards, Jö

Hello Jo,

Thank you for your answer,

I have a Juniper running rstp connected with a cisco running pvst and they are working fine now i want to connect a stack of 3810M in the Juniper and the options of 3810M is mstp and pvst.The root is the cisco.So what is the compatible i should use ?

The connection will be as follow

3810M(?)<------>RSTP(Juniper)<------>PVST(Cisco (Root))

Hi,

you have to be very careful with that.

• PVST sends BPDUs with VLAN Tag. RSTP/MSTP send everything untagged
• Depending on VLAN 1 configured native on a trunk or non-nativ, PVST will use the same multicast mac address or a different one.

This can lead to a situation, where the differnet devices do not recognize each others spanningtree. Often resulting forwarding situation will be as you planned, but somtimes it will be different.

Sadly I do not have an official reference which I could share.

But if you search for "Holger Hasenaug" "Cisco" Procurve" "interoperable". He wrote a presentation named "HP / Cisco interoperability and migration scenario".   Maybe you add "Vincent Giles" I know of a newer version of the presentation, they did togehter.

Another document is "Migrating from Cisco to
HP ProCurve Networks". This one can be found here: http://kb.kaminskiengineering.com/sites/kb.kaminskiengineering.com/files/support_files/HP%20Procurve%20Migrating%20from%20Cisco%20to%20ProCurve%20Networks.pdf 

I know both documents from the pre HPE/Aruba merger times. But since spanningtree didn't change much, they are still valid.

Although this is written with Cisco and Procurve in mind, this contains general information about Cisco vs. RestOfWorld ;-)

Someone at HPE/Aruba, maybe you can chime and provide valid links to these documents?

Regards, Jö

Juniper VSTP ( vlan spanning tree protocol) equal to cisco PVST/PVSTP+