A routing loop is a state in which the packet is processed over and over by a series of routers ( it goes in a circle ). To deal with such packets, IP has TTL ( Time To Live ) field in the header. Max value is 255, but default value can vary depending on OS, however, TTL is decremented each time it passes through a router. When it reaches 0, the packet is discarded.
In opposite to frames, wich does not have such feature, when L2 loop occurs, frames caught in the loop are processed "forever".
In "normal" network which is configured properly, routing loops should not occur.
This problem can arise, for example, by bad redistribution. For an example, how routing loop can occur during redistribution, see the link below:
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 customers befor...
Introduction Featured Speakers Luis Espejel is the Telecommunications
Manager of IENova, an Oil & Gas company. Currently he works with Cisco
IOS® and Cisco IOS XE platforms, and NX to some extent. He has also
worked as a Senior Engineer with the Routing P...
In this session you can learn more about Layer 3 multicast and the best
practices to identify possible threats and take security measures. It
provides an overview of basic multicast, the best security practices for
use of this technology, and recommendati...