  Many models of virus propagation in Computer Networks inspired by {\bf
SIS,SIR,}\\ {\bf SEIR}, etc. epidemic disease propagation mathematical models
that can be found in the epidemiology field have been proposed in the last two
decades. The purpose of these models has been to determine the conditions under
which a virus becomes rapidly extinct in a network. The most common models
proposed in the field of virus propagation in networks are inspired by SIS-type
models or their variants. In such models, the conditions that lead to a rapid
extinction of the spread of a computer virus have been calculated and its
dependence on some parameters inherent to the mathematical model has been
observed. In this article we will try to analyze a particular model proposed in
the past and show through simulations the influence that topology has on the
dynamics of the spread of a virus in different networks. A consequence of
knowing the impact of the topology of a network can serve to propose effective
isolation strategies to reduce the spread of a virus through modifications to
the original network of contacts. I will talk about this subject at the final
section of the present article.
