can ping but cannot get to www or cannot ping by name

can ping but cannot get to www or cannot ping by name

Post by Rich » Mon, 15 Oct 2001 00:59:35



   internet
        |
Linksys Router
     1.1.1.1
         |
 ---1.1.1.2--
 | linux router|      <---Machine A
 |  redhat      |
 ---1.1.2.1--
         |
 ---1.1.2.3--
|   linux        |        <---Machine B
|   redhat     |
-------------

Above is how things are setup at my house(excuse the drawing).

From Machine B, I can ping machine A(both ethernet) and I can ping Linksys
Router and Also ping the ip address that is out on the internet.

From Machine A, I can ping everything(including the name (like yahoo.com)
out on the internet).

For my Machine B, I have the same configuration on /etc/resolv.conf

It looks like, on Machine A, I am running ipchains(iptables is installed but
I guess I can't run both at the sametime).

When I do ipchains -h, below is part of results I get

Chain forward (policy DENY):
target     prot opt     source                destination           ports
MASQ       all  ------  192.168.2.0/24       anywhere              n/a

Considering I am total newbie, I think I have done well so far, but I need
some friendly advice ;-)

ps: also, why would somebody run ipchains versus iptables? what's better?
Can it be run at the sametime(why would anybody want to?)

Thanks in advance.

 
 
 

can ping but cannot get to www or cannot ping by name

Post by Dean Thompso » Mon, 15 Oct 2001 23:25:49


Hi!,

Quote:> Above is how things are setup at my house(excuse the drawing).

> From Machine B, I can ping machine A(both ethernet) and I can ping Linksys
> Router and Also ping the ip address that is out on the internet.

> From Machine A, I can ping everything(including the name (like yahoo.com)
> out on the internet).

> For my Machine B, I have the same configuration on /etc/resolv.conf

> It looks like, on Machine A, I am running ipchains(iptables is installed
> but I guess I can't run both at the sametime).

Check to make sure that Machine B has got the DNS ISP configured in its
/etc/resolv.conf file.  Additionally, check to make sure that your iptables
are allowing you to accept the UDP packets coming back from your domain name
server which contains the hostname to IP address translation.  It might be a
good idea to take a look at the firewall log on machine B and see which
packets if any are being rejected.  I presume that Machine A has got its IP
forwarding working correctly and that machine A is doing the masq'ing of
connections (I suppose that would be working if Machine B can ping the outside
world).

See ya

Dean Thompson

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can ping but cannot get to www or cannot ping by name

Post by Bill Unr » Tue, 16 Oct 2001 06:07:26



I hope thse are NOT the addresses you actually use. Please make that first number a
10 not .
10.1.1.1, and sim for all the others.

]   internet
]        |
]Linksys Router
]     1.1.1.1
]         |
] ---1.1.1.2--
] | linux router|      <---Machine A
] |  redhat      |
] ---1.1.2.1--
]         |
] ---1.1.2.3--
]|   linux        |        <---Machine B
]|   redhat     |
]-------------

]Above is how things are setup at my house(excuse the drawing).

]From Machine B, I can ping machine A(both ethernet) and I can ping Linksys
]Router and Also ping the ip address that is out on the internet.

Not with those addresses you cannot. They do not belong to you and there is no way
any machine will respond to you. You may also get the true owner rather pissed off.
Use the 10.x.x.x addresses. Thereafter you mush make sure ip forwarding it enabled
and (if you use the 10. addresses) that ip masquarading is enabled.

]From Machine A, I can ping everything(including the name (like yahoo.com)
]out on the internet).

]For my Machine B, I have the same configuration on /etc/resolv.conf

]It looks like, on Machine A, I am running ipchains(iptables is installed but
]I guess I can't run both at the sametime).

]When I do ipchains -h, below is part of results I get

]Chain forward (policy DENY):
]target     prot opt     source                destination           ports
]MASQ       all  ------  192.168.2.0/24       anywhere              n/a

]Considering I am total newbie, I think I have done well so far, but I need
]some friendly advice ;-)

]ps: also, why would somebody run ipchains versus iptables? what's better?
]Can it be run at the sametime(why would anybody want to?)

]Thanks in advance.

 
 
 

can ping but cannot get to www or cannot ping by name

Post by Rich » Wed, 17 Oct 2001 14:14:57


Sorry, I didn't make this clear.

I am using 192.168.2 and 192.168.1

I will try with your suggestions on to see if it makes any difference.

Thank you very  much for the feedbak though.

I will keep everyone in loop.

Thanks.




> I hope thse are NOT the addresses you actually use. Please make that first
number a
> 10 not .
> 10.1.1.1, and sim for all the others.

> ]   internet
> ]        |
> ]Linksys Router
> ]     1.1.1.1
> ]         |
> ] ---1.1.1.2--
> ] | linux router|      <---Machine A
> ] |  redhat      |
> ] ---1.1.2.1--
> ]         |
> ] ---1.1.2.3--
> ]|   linux        |        <---Machine B
> ]|   redhat     |
> ]-------------

> ]Above is how things are setup at my house(excuse the drawing).

> ]From Machine B, I can ping machine A(both ethernet) and I can ping
Linksys
> ]Router and Also ping the ip address that is out on the internet.

> Not with those addresses you cannot. They do not belong to you and there
is no way
> any machine will respond to you. You may also get the true owner rather
pissed off.
> Use the 10.x.x.x addresses. Thereafter you mush make sure ip forwarding it
enabled
> and (if you use the 10. addresses) that ip masquarading is enabled.

> ]From Machine A, I can ping everything(including the name (like yahoo.com)
> ]out on the internet).

> ]For my Machine B, I have the same configuration on /etc/resolv.conf

> ]It looks like, on Machine A, I am running ipchains(iptables is installed
but
> ]I guess I can't run both at the sametime).

> ]When I do ipchains -h, below is part of results I get

> ]Chain forward (policy DENY):
> ]target     prot opt     source                destination           ports
> ]MASQ       all  ------  192.168.2.0/24       anywhere              n/a

> ]Considering I am total newbie, I think I have done well so far, but I
need
> ]some friendly advice ;-)

> ]ps: also, why would somebody run ipchains versus iptables? what's better?
> ]Can it be run at the sametime(why would anybody want to?)

> ]Thanks in advance.

 
 
 

1. A pings B, B pings C, C cannot ping A

In our small network, we have several w9x clients, a w2k server and a
linux server. To date, integration of these has been going ok. However,
today, we brought up some clients that cannot ping to the linux server
(all of this by IP address), but they can ping to the w2k server, which
are physically next to each other, and connect to the same switch. There
have been no problems with communication between the linux system, w2k
system and other computers on site. The clients use dhcp on the w2k
server to get their ip addresses. The only issues that I can think of at
this time is that the problem systems are on the longest runs from the
hub, which appear to be a little over the 100m line, and the linux and
w2k units (probably) have different nics. Can anybody out there shed
some light on this situation?

Thanks,

Sent via Deja.com
http://www.deja.com/

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