https://community.extremenetworks.com/t5/extremeswitching-other/ers-spbm-limitations/m-p/84633#M3935 An older matrix shows that the 4800 models can't be a BCB in an SPBM environment. Is that the case for the ERS4900? From what I can tell, it does work as a BCB. Tue, 05 Apr 2022 23:08:07 GMT bfaltys 2022-04-05T23:08:07Z https://community.extremenetworks.com/t5/extremeswitching-other/ers-spbm-limitations/m-p/84633#M3935 An older matrix shows that the 4800 models can't be a BCB in an SPBM environment. Is that the case for the ERS4900? From what I can tell, it does work as a BCB. Tue, 05 Apr 2022 23:08:07 GMT https://community.extremenetworks.com/t5/extremeswitching-other/ers-spbm-limitations/m-p/84633#M3935 bfaltys 2022-04-05T23:08:07Z https://community.extremenetworks.com/t5/extremeswitching-other/ers-spbm-limitations/m-p/84634#M3936 ERS4900 and ERS5900 both have BCB support (NNI to NNI forwarding) Wed, 06 Apr 2022 16:33:30 GMT https://community.extremenetworks.com/t5/extremeswitching-other/ers-spbm-limitations/m-p/84634#M3936 Ludovico_Steven 2022-04-06T16:33:30Z https://community.extremenetworks.com/t5/extremeswitching-other/ers-spbm-limitations/m-p/84635#M3937 Thanks. Just for my own knowledge, does ERS4800 not have NNI->NNI support? Wed, 06 Apr 2022 16:47:17 GMT https://community.extremenetworks.com/t5/extremeswitching-other/ers-spbm-limitations/m-p/84635#M3937 bfaltys 2022-04-06T16:47:17Z https://community.extremenetworks.com/t5/extremeswitching-other/ers-spbm-limitations/m-p/84636#M3938 No, the ERS4800 never had NNI-NNI forwarding support. So it always activates ISIS Overload as well, which basically prevent the SPB node from even being considered as transit on paths to other destinations. Wed, 06 Apr 2022 18:52:17 GMT https://community.extremenetworks.com/t5/extremeswitching-other/ers-spbm-limitations/m-p/84636#M3938 Ludovico_Steven 2022-04-06T18:52:17Z