OSPF & ISIS

Hi,

OSPF and ISIS use similar algorithms and provide similar preformance. Due to various reasons, more enterprises deploy OSPF and many engineers are more familiar with OSPF in the enterprise network market. 

Conclusion:

OSPF has more flexible routing, richer routing control methods and is more suitable for hierarchical division. In an enterprise escenario you can consider placing high performance devices in the OSPF backbone area and less performance in NSSA and STUB areas. ISIS has faster convergence speed, strong scalability, and better network stability. At present, it is mostly used in carrier networks with flat network designs. 

Here is also a good post with more details about this two protocols that can help you out to take the best desicion:

https://forum.huawei.com/enterprise/en/ospf-vs-isis/thread/570007-863

Hi LSA,
There are many posts on the differences between OSPF and ISIS in the forum. You can refer to

You can also refer to

HCIE Interview question – OSPF vs ISIS - Huawei Enterprise Support Community

OSPF Vs ISIS - Huawei Enterprise Support Community

ISIS has a better expansibility than OSPF does, for example, isis can support ipv6 while OSPF doesn't, if we want the OSPF support ipv6, we have to enable OSPF v3, rather than OSPF.
what's more, isis can bear a larger-scale network topology and devices than OSPF, this is quite important in the ISP network environment, ISP contains a lot of devices usually.
besides, isis works on the data link layer, OSPF is based on IP which works on the network layer, this advantage gives more expansibility to isis than OSPF.

Glad to help you! Any further questions, let us know