Re: [CentOS] 2 questions on CentOS firewall

2011-07-21 Thread Timothy Murphy
Ljubomir Ljubojevic wrote: I take a look at Billion manual. It seams that you have to use it's firewall to add an allow rule for protocol icmp? and source IP 0.0.0.0. Destination might be also 0.0.0.0, haven't had the time to study it. This should allow pings from outside. Thanks very much.

Re: [CentOS] 2 questions on CentOS firewall

2011-07-20 Thread Timothy Murphy
Timothy Murphy wrote: Ljubomir Ljubojevic wrote: (1) I can open port 22 on the Billion, allowing me to ssh in from outside. But for some reason I cannot ping the same address from outside. This is due to modem refuses to answer to pings. You might have option to allow it in modem

Re: [CentOS] 2 questions on CentOS firewall

2011-07-20 Thread Ljubomir Ljubojevic
Timothy Murphy wrote: Further to my question, how can I determine if it is the Billion 5200S modem/router that is preventing pings, or if it is the CentOS-6 MicroServer attached to the modem/router? I don't see any reference to ICMP on the modem web-page. On the other hand the CentOS

Re: [CentOS] 2 questions on CentOS firewall

2011-07-20 Thread Markus Falb
On 20.7.2011 12:51, Timothy Murphy wrote: Further to my question, how can I determine if it is the Billion 5200S modem/router that is preventing pings, or if it is the CentOS-6 MicroServer attached to the modem/router? ... Is there any simple way, short of using something like ethereal, of

Re: [CentOS] 2 questions on CentOS firewall

2011-07-20 Thread Always Learning
On Wed, 2011-07-20 at 14:21 +0200, Ljubomir Ljubojevic wrote: Ljubomir Ljubojevic (Love is in the Air) Congratulations. Are you planning to invite us to the wedding :-) -- With best regards, Paul. England, EU. ___ CentOS mailing list

Re: [CentOS] 2 questions on CentOS firewall

2011-07-20 Thread Les Mikesell
On 7/20/2011 5:51 AM, Timothy Murphy wrote: Further to my question, how can I determine if it is the Billion 5200S modem/router that is preventing pings, or if it is the CentOS-6 MicroServer attached to the modem/router? I don't see any reference to ICMP on the modem web-page. On the

Re: [CentOS] 2 questions on CentOS firewall

2011-07-20 Thread Ljubomir Ljubojevic
Always Learning wrote: On Wed, 2011-07-20 at 14:21 +0200, Ljubomir Ljubojevic wrote: Ljubomir Ljubojevic (Love is in the Air) Congratulations. Are you planning to invite us to the wedding :-) Hehehehe, no. My first name (Ljubomir) is old Slavic name that means He who loves peace,

Re: [CentOS] 2 questions on CentOS firewall

2011-07-20 Thread Timothy Murphy
Markus Falb wrote: I would use tcpdump on the CentOS Server to be sure the icmp echo requests are arriving or not. tcpdump is something like ethereal but it could be as easy as $ tcpdump -l proto \\icmp or $ tcpdump -l proto \\icmp and host sourceip or $ tcpdump -li ethX proto \\icmp

Re: [CentOS] 2 questions on CentOS firewall

2011-07-20 Thread Ljubomir Ljubojevic
Timothy Murphy wrote: Markus Falb wrote: I would use tcpdump on the CentOS Server to be sure the icmp echo requests are arriving or not. tcpdump is something like ethereal but it could be as easy as $ tcpdump -l proto \\icmp or $ tcpdump -l proto \\icmp and host sourceip or $ tcpdump

Re: [CentOS] 2 questions on CentOS firewall

2011-07-20 Thread Timothy Murphy
Ljubomir Ljubojevic wrote: ICMP packets are blocked by Billion, it's 99% chance, since public IP resides on the Billion. Only way (known to me) to pass ICMP to your CentOS server (on cheap modem/routers) is to do 1:1 NAT (all connections to all ports are redirected to system behind it with

Re: [CentOS] 2 questions on CentOS firewall

2011-07-20 Thread Timothy Murphy
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:

Re: [CentOS] 2 questions on CentOS firewall

2011-07-20 Thread Ljubomir Ljubojevic
Timothy Murphy wrote: 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?

Re: [CentOS] 2 questions on CentOS firewall

2011-07-19 Thread Ljubomir Ljubojevic
Timothy Murphy wrote: I'm running CentOS-6 on an HP MicroServer with a Billion 5200S modem/router connecting to the internet. I'm running the standard CentOS-6 firewall on the server. (1) I can open port 22 on the Billion, allowing me to ssh in from outside. But for some reason I cannot

Re: [CentOS] 2 questions on CentOS firewall

2011-07-19 Thread Robert Spangler
On Tuesday 19 July 2011 09:11, the following was written: Timothy Murphy wrote: I'm running CentOS-6 on an HP MicroServer with a Billion 5200S modem/router connecting to the internet. I'm running the standard CentOS-6 firewall on the server. (1) I can open port 22 on the Billion,

Re: [CentOS] 2 questions on CentOS firewall

2011-07-19 Thread Timothy Murphy
Ljubomir Ljubojevic wrote: (1) I can open port 22 on the Billion, allowing me to ssh in from outside. But for some reason I cannot ping the same address from outside. This is due to modem refuses to answer to pings. You might have option to allow it in modem config. Ping (ICMP) does not

Re: [CentOS] 2 questions on CentOS firewall

2011-07-19 Thread Ljubomir Ljubojevic
Robert Spangler wrote: On Tuesday 19 July 2011 09:11, the following was written: Timothy Murphy wrote: I'm running CentOS-6 on an HP MicroServer with a Billion 5200S modem/router connecting to the internet. I'm running the standard CentOS-6 firewall on the server. (1) I can