Re: Anyone can explain interface pfe, pfh, lc and irb briefly?
The first 3 listed are intra-chassis or internal interfaces and irb is the integrated routing and bridging interface, i.e L3 interface on a bridged network:
lc—Internally generated interface that is not configurable.
PFH interfaces are pseudo/virtual interfaces, which represent the PFE Host Processor (the processor hosting the PFE, which is usually the FPC for distributed routers and the SCB/SSB/SFM boards for old single-PFE or centralized forwarding routers). It is used for intra-chassis communication and is not user-configurable.