c3560 switch is not allowing telnet or SSH

Question:

I have configured new WS-C3750X-12S-S  DS3 link as below.Also GRE tunnel build on it.EIGRP running between tunnel interfaces.
EIGRP is flapping every minute , i dont found any packet drop between 2 routers WAN interfaces, but ping stcuks for some time.
During this time EIGRP flaps.ISP dont found any issue in network.


int s4/0
ip add x.x.x.x
encapsulation ppp
dsu bandwidth 44210
scramble
crc 32
serial restart-delay 0

interface Tunnel155
  bandwidth 25000
ip address A.B.C.D
no ip redirects
no ip proxy-arp
ip tcp adjust-mss 1432
load-interval 30
delay 100
qos pre-classify
keepalive 10 3
tunnel source Serial4/0
tunnel destination YY.Y.Y.

Answer:

Did you check the IP MTU on both sides of the tunnel? You might want to reduce the MTU size according to how much your physical link supports. WS-C3750X-24S-S Price   For more info, http://www.pereza.info/es/blog/2811-router-needs-be-reloaded-every-week