Question re ADSL router

Discussion in 'Computer Support' started by Jimmy Dean, Dec 4, 2005.

  1. Jimmy Dean

    Jimmy Dean Guest

    I have a Netgear 534 ADSL modem/router from which several peer-to-peer
    LAN PCs connect to the Net.

    The router's firewall is set by default to block all incoming traffic,
    yet somehow I am still able to get e-mail, WWW, newsgroups etc.
    without specifying specific rules to allow these type of traffic.

    Just wondering how that is possible...

    jd
     
    Jimmy Dean, Dec 4, 2005
    #1
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  2. Jimmy Dean

    Pat Guest

    On Sun, 04 Dec 2005 12:10:22 +1100, Jimmy Dean <>
    wrote:

    >I have a Netgear 534 ADSL modem/router from which several peer-to-peer
    >LAN PCs connect to the Net.
    >
    >The router's firewall is set by default to block all incoming traffic,
    >yet somehow I am still able to get e-mail, WWW, newsgroups etc.
    >without specifying specific rules to allow these type of traffic.
    >
    >Just wondering how that is possible...
    >
    >jd


    Because the router will let outgoing request and the response through,
    unless you specifically block outgoing traffic. It is blocking
    unsolicited incoming traffic. My D-Link has a setup page that has IP
    filters to allow or deny an individual LAN IP address or a range of LAN
    IP addresses access to the WAN. There is no application level control.
    For that you need a software firewall running on each PC. A NAT router
    won't do that.

    --
    Pat
     
    Pat, Dec 4, 2005
    #2
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  3. Jimmy Dean

    Duane Arnold Guest

    Pat <> wrote in news:rbn4p1dsoa3gsh64gngohq818uot0g5vk4@
    4ax.com:

    > On Sun, 04 Dec 2005 12:10:22 +1100, Jimmy Dean <>
    > wrote:
    >
    >>I have a Netgear 534 ADSL modem/router from which several peer-to-peer
    >>LAN PCs connect to the Net.
    >>
    >>The router's firewall is set by default to block all incoming traffic,
    >>yet somehow I am still able to get e-mail, WWW, newsgroups etc.
    >>without specifying specific rules to allow these type of traffic.
    >>
    >>Just wondering how that is possible...
    >>
    >>jd

    >
    > Because the router will let outgoing request and the response through,
    > unless you specifically block outgoing traffic. It is blocking
    > unsolicited incoming traffic. My D-Link has a setup page that has IP
    > filters to allow or deny an individual LAN IP address or a range of LAN
    > IP addresses access to the WAN. There is no application level control.
    > For that you need a software firewall running on each PC. A NAT router
    > won't do that.
    >


    A packet filtering FW router can set a rule to block all inbound traffic
    to the network. One can then set rules to allow specified inbound traffic
    into the network. Those are high-end packet filtering FW routers that are
    not the typical routers used in the home. FW appliances have this ability
    too. One can also just set a rule to block all outbound traffic as well
    with the devices and set rules to allow specified outbound traffic.

    What does a network/Internet FW do?

    http://www.firewall-software.com/firewall_faqs/what_does_firewall_do.html

    Duane :)
     
    Duane Arnold, Dec 4, 2005
    #3
  4. Jimmy Dean

    Evan Platt Guest

    On Sun, 04 Dec 2005 12:10:22 +1100, Jimmy Dean <>
    wrote:

    >I have a Netgear 534 ADSL modem/router from which several peer-to-peer
    >LAN PCs connect to the Net.
    >
    >The router's firewall is set by default to block all incoming traffic,
    >yet somehow I am still able to get e-mail, WWW, newsgroups etc.
    >without specifying specific rules to allow these type of traffic.
    >
    >Just wondering how that is possible...


    Simple - when you make an outgoing request, traffic is allowed back on
    that port that you sent a request out on - mail is port 25 or 110
    (send / receive), web is 80, etc.
    --
    To reply, remove TheObvious from my e-mail address.
     
    Evan Platt, Dec 4, 2005
    #4
  5. Jimmy Dean

    Jimmy Dean Guest

    On Sat, 03 Dec 2005 22:33:30 -0800, Evan Platt
    <> wrote:

    >On Sun, 04 Dec 2005 12:10:22 +1100, Jimmy Dean <>
    >wrote:
    >
    >>I have a Netgear 534 ADSL modem/router from which several peer-to-peer
    >>LAN PCs connect to the Net.
    >>
    >>The router's firewall is set by default to block all incoming traffic,
    >>yet somehow I am still able to get e-mail, WWW, newsgroups etc.
    >>without specifying specific rules to allow these type of traffic.
    >>
    >>Just wondering how that is possible...

    >
    >Simple - when you make an outgoing request, traffic is allowed back on
    >that port that you sent a request out on - mail is port 25 or 110
    >(send / receive), web is 80, etc.


    Thanx. Makes sense, and the only answer so far that really addressed
    the question...

    jd
     
    Jimmy Dean, Dec 4, 2005
    #5
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