When performing a passive packet capture of a network, I have seen a large amount of traffic being broadcast using different protocols. These protocols are primarily used to perform some kind of traffic routing/fail over/redundancy in case a device goes down in the topology.
Several of these protocols have known weaknesses and can be used to manipulate traffic flows between networking devices. For example HSRP is seen as broadcasting authentication data with a clear text password. This is bad and can be exploited using software like 'Yersinia' to perform interception and denial of service attacks.
My main question is: Assuming that the presence of these protocols is required for operations, should I be seeing them in all subnets, including those only used by 'users' or can they be constrained in some way to a specific management only subnet while still providing functionality?
The protocols i'm looking at are:
I'm also interested in any other protocols I might have missed that might fall into the category of 'network management protocols that can be abused by an attacker on the local subnet'.