I have a few queries. I would appreciate if you could help me in clearing these doubts
1. Regarding Link Efficiency Mechanisms. In the books I could find only this in a nutshell --
"1. On slow links configure LFI.
2. If using HDLC or PPP use link payload compression, if using ATM or Frame relay , use layer 2 payload compression.
3. If voice, use Header Compression.
Can we use both Layer 2 payload compression and Header compression on WAN links? What is recommended?
2. On the distribution switches, why is this command recommended as a good design practice( referring to the Net design guide by Cisco from 1995)-
mls ip cef load-sharing full
It was talking something about Left/Left , Right/Right path taken,L3/L4 hash and load sharing not taken care of properly.
I could not understand this concept.
3. On which ports is it recommended to apply mls qos trust cos and on which ports is it recommended to apply mls qos trust DSCP? Does it depend on whether we have marked Cos and DSCP and if the ports are layer 2 or layer 3. I mean after marking on access layer, on the upper layers (dist/core), how do we determine whether to trust cos or dscp?
4.When desgining OSPF is it recommended to have the area 0 between Distribution and Core. This question stems from a reading which says that to reduce SPF and LSA load to area 0 , summarize on distribution to core.