[CentOS] 2 questions on CentOS firewall

Timothy Murphy gayleard at eircom.net
Wed Jul 20 20:41:46 UTC 2011


Timothy Murphy wrote:

> So I assume the modem is rejecting the ICMP packets.
> As I said, I don't see anything about this
> in the modem documentation or on the modem web-site.

I suppose another possibility is that some site along the way
rejects ICMP packets?

traceroute seems to timeout in Milan:
-----------------------------------
[root at helen tim]# traceroute anghiari.homelinux.com
traceroute to anghiari.homelinux.com (79.46.6.203), 30 hops max, 40 byte 
packets
 1  netopia (192.168.1.254)  0.951 ms  1.132 ms  1.389 ms
 2  isp (159.134.155.19)  37.238 ms  39.560 ms  42.027 ms
...
12  telecomitalia.par02.atlas.cogentco.com (130.117.14.82)  67.140 ms 
telecomitalia.par02.atlas.cogentco.com (130.117.15.138)  92.952 ms ibs-
resid.milano50.mil.seabone.net (93.186.128.246)  87.098 ms
13  * * *
...
30  * * *
-----------------------------------
tcptraceroute gets to the modem, but after some timeouts:
-----------------------------------
[root at helen tim]# tcptraceroute anghiari.homelinux.com
traceroute to anghiari.homelinux.com (79.46.6.203), 30 hops max, 40 byte 
packets
 1  netopia (192.168.1.254)  1.491 ms  1.534 ms  1.784 ms
 2  isp (159.134.155.19)  36.195 ms  38.794 ms  41.328 ms
...
12  ibs-resid.milano50.mil.seabone.net (93.186.128.246)  85.084 ms  84.599 
ms  86.881 ms
13  * * *
14  * * *
15  * * *
16  * * *
17  * * *
18  host203-6-dynamic.46-79-r.retail.telecomitalia.it (79.46.6.203)  115.381 
ms  107.416 ms  114.875 ms
-----------------------------------

If anyone can interpret these for me, I shall be grateful.

-- 
Timothy Murphy  
e-mail: gayleard /at/ eircom.net
tel: +353-86-2336090, +353-1-2842366
s-mail: School of Mathematics, Trinity College, Dublin 2, Ireland




More information about the CentOS mailing list