linux server stamathse na apanta se pings

[Stoilis Giannis]

V13 wrote:


> Sto mixanima sto opoio kaneis ping trekse 'tcpdump -ni any icmp' kai kanto 
> ping blepontas an stelnei tipota, oste na eisai sigoyros oti den apantaei apo 
> allo interface... 

Me koufanes twra. Des ti anakalupsa:

An treksw "tcpdump | grep icmp" pairnw auto:
21:40:58.758459 10.0.0.16 > 10.0.0.14: icmp: echo request (DF)
21:40:59.758499 10.0.0.16 > 10.0.0.14: icmp: echo request (DF)
21:41:00.758477 10.0.0.16 > 10.0.0.14: icmp: echo request (DF)
21:41:01.758514 10.0.0.16 > 10.0.0.14: icmp: echo request (DF)
21:41:02.758547 10.0.0.16 > 10.0.0.14: icmp: echo request (DF)

An treksw thn entolh sou "tcpdump -ni any icmp" pairnw auto:
21:42:35.758793 10.0.0.16 > 10.0.0.14: icmp: echo request (DF)
21:42:35.758821 10.0.0.14 > 10.0.0.14: icmp: echo reply
21:42:36.758778 10.0.0.16 > 10.0.0.14: icmp: echo request (DF)
21:42:36.758807 10.0.0.14 > 10.0.0.14: icmp: echo reply
21:42:37.758819 10.0.0.16 > 10.0.0.14: icmp: echo request (DF)
21:42:37.758852 10.0.0.14 > 10.0.0.14: icmp: echo reply
21:42:38.758778 10.0.0.16 > 10.0.0.14: icmp: echo request (DF)
21:42:38.758825 10.0.0.14 > 10.0.0.14: icmp: echo reply
21:42:39.758835 10.0.0.16 > 10.0.0.14: icmp: echo request (DF)
21:42:39.758885 10.0.0.14 > 10.0.0.14: icmp: echo reply

Parathrhse oti ta reply exoun idio source kai destination ip!!!

> Ping sto eayto toy(127.0.0.1) kanei ?
nai

 > Ping apo ton eayto toy stis kartes diktyoy toy ?
nai

 > Otan les kanenas den toy kanei ping eisai sigoyros gia to *kanenas*?
nai

> Sigoyrepsoy oti den exei pragmati kanena roule sto iptables se kanena 
> table(kai oxi mono sto filter)...

koitaksa kai se alla tables. Tipota...

> An kaneis ifconfig eth0 down, ifconfig eth1 down kai meta tis ksanasikoseis 
> doylevei ?
oxi

Now we are getting somewhere...

- Giannis