Apparently the question of whether IS-IS is a layer 2 protocol or a layer 3 protocol falls into the realm of religious wars. It's one I had never been near; the issue had never come up for me. But I like Tony Li's statement, https://www.quora.com/Why-is-ISIS-considered-a-layer-2-protocol-and-OSPF-a-layer-3-one-yet-theyre-often-swapped-one-for-the-other
"I’ll disagree completely with the categorization to start with. There is no functional or logical difference between them, so I see no point in putting them in different layers. It’s very true that IS-IS runs directly on top of the link layer while OSPF runs on top of IP. However, that doesn’t matter a whit, that’s just the implementation details, not the true functionality. If we went just by the mechanisms, that would put BGP as an application protocol. Ummm naaa. >From a functional perspective, routing protocols are purely part of the L3 network layer. Their purpose is simple: take topology information, compute paths and control L3 forwarding. That’s the function, and that’s the layer that it belongs to." Burt On Mon, Apr 30, 2018 at 9:54 AM, Chris Luke <chris_l...@comcast.com> wrote: > IS-IS is not an IP protocol, it’s a layer 2 protocol, meaning it has its > own Ethertype. > > > > Chris. > > > > *From:* vpp-dev@lists.fd.io [mailto:vpp-dev@lists.fd.io] *On Behalf Of * > Gulakh > *Sent:* Monday, April 30, 2018 9:42 AM > *To:* vpp-dev@lists.fd.io > *Subject:* [vpp-dev] router plugin ISIS > > > > Hi, > > i want to extend router plugin code to support is-is, i.e., sending is-is > packets up to the control plane! > > First, i registered ISIS in tap inject, by adding the following line: > ip4_register_protocol (IP_PROTOCOL_ISIS, im->tx_node_index); > > in tap_inject_enable (void) function located at > vppsb/router/router/tap_inject.c > file! > > However, the problem remained unsolved. > > Is there a special issue related to is-is that i should know? > > Anyone can help me? > > Regards, > > Gulakh > > > >
