Hi All,
My 3821 DMVPN hub router has this configuration and the MTU may be higher than it should be.
interface Tunnel0
description Tunnel for DMVPN
bandwidth 4500
ip address 10.x.x.x 255.255.255.224
no ip redirects
ip mtu 1416
no ip next-hop-self eigrp 170
ip nhrp authentication ots
ip nhrp map multicast dynamic
ip nhrp network-id 100
ip nhrp holdtime 360
ip nhrp cache non-authoritative
ip tcp adjust-mss 1360
no ip split-horizon eigrp 170
delay 1000
qos pre-classify
tunnel source Multilink1
tunnel mode gre multipoint
tunnel key 100000
tunnel protection ipsec profile otsvpn
end
I have 3 three questions:
What do you recommend for the MTU and MSS size for a DMVPN tunnel interface which use a multilink PPP interface as a tunnel source?
what's the overhead bytes of
GRE = 24 ??
IPsec = 52 ??
outside IP header = 20 bytes
MLPPP = ??
Should I enable fragmentation on the MLPPP interface? will these commands reduce latency and jitter?
ppp multilink fragment delay 10
ppp multilink interleave
Thank you in advance for any info.
PH
