ISIS came out first followed by OSPF. Some ISPs were already running ISIS when OSPF came out and some others decided to go with the relative maturity of former when the latter came out.
There is advantages and disadvantages for both. I personally like ISIS as I feel you can scale it better without requiring to split your core in multiple levels (area in the OSPF terminology). For instance ISIS allows you to only advertise the Loopback interface IP address for each router (not yet available in OSPF). The other link prefixes can then be carried in BGP.
ISIS is also relatively easy to extend to support new protocols (Address Families) as only the addition of one or more TLVs (Type, Length, Value) is required.
OSPF on the other hand has more features and knobs to fine tune and adapt to a given network as it is widely used in the enterprise world.
Bottom line today is what protocol one feels most comfortable with.
Harold Ritter Sr. Technical Leader CCIE 4168 (R&S, SP) email@example.com México móvil: +52 1 55 8312 4915 Cisco México Paseo de la Reforma 222 Piso 19 Cuauhtémoc, Juárez Ciudad de México, 06600 México
1. Introduction Internet security is important with the increasing
attacks that are happening every day. Many internet and browsing
security solutions exist, but some are not very easy to use or maybe the
question is how can I enable them? In this referen...
Cisco Software Manager Server API Guide This document describes the
programmatic interfaces, RESTful APIs, which are supported by Cisco
Software Manager Server (CSM Server). Overview CSM Server supports a set
of finite RESTful APIs. The first step to use ...
If you are using Cisco's new linux-based Cisco Software Manager server,
then you probably want to make sure there is a startup service for
it.I'll assume that you've already installed the CSM server on a
systemd-based linux system. The commands given belo...