November 8, 2023 ↩

Multiprotocol label switching (MPLS)

• Goal : high-speed IP forwarding among network of MPLS-capable routers, used fixed length label (instead of shortest prefix matching)
• Router should be able to identify MPLS (aka label-switched router).

MPLS vs IP:

• IP routing: path to destination determined by destination address alone.
• IP/MPLS entry router can use different MPLS routers to A based on IP source address or other fields.
• MPLS routing: path to destination determined on destination address as well as source.
  • flavor of generalized forwarding (MPLS 10 years earlier)
  • Fast rerouting

In regard to MPLS forwarding tables, for routers there are no tables in the data link layer. Only one layer.

Go through Datacenter Networking.

Firewall

• Isolates org’s internal network from larger internet, allowing some packets to pass, blocking others.

Q. Why?
It prevents denial of service attacks - SYN flooding where attacker establishes many bogus TCP connections, no resources left for “real” connections.
It prevents illegal modification/access of internal data.

Cisco sells a box that’s a firewall. It’s both a firewall as well as a router. IP tables?

Stateless packet-filtering : Network connected via router’s firewall.