You are partly correct. RIP v1 doesn't net send subnet mask info in it's updates. RIP v1 doesn't support VLSM. But, it does support fixed length subnet mask.
Take a look at this example. In the below scenario, both R1 & R2 run RIP v1 on all the interfaces. Since R1's ethernet and s0 are configured with the same subnet mask it would send a routing update for 192.168.1.0. R2 knowing the subnet mask is 255.255.255.224 on it's s0 interface it would apply the same subnet mask for the 192.168.1.0 it learnt from R1.
We are pleased to announce availability of Beta software for 16.6.3. 16.6.3 will be the second rebuild on the 16.6 release train targeted towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are looking for early feedback from custome...