Questions

How to setup Cisco Loopback

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How to setup Cisco Loopback

beigemonkey
I have a cisco 1841 router with T1 setup and behind are couple of servers hosting my website abc.com and a few pc. I tried to browse my website abc.com from a pc and it goes no where. If I add DNS record abc.com to my internal DNS server and point it to the internal LAN server IP and it works. It there there anyway to setup the Cisco router to access loopback without adding an internal DNS record.

I also have a site forum.abc.com that's hosted in the cloud and it uses forwarding URL. I cannot add forwarding in the internal DNS. Any help would greatly appreciated.
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    David-123

    A loopback interface is generally used by routers or Layer 3 capable switches so that they have a reliable IP interface for routing updates.

    In other words, a loopback interface is a special virtual interface created in software.

    It has no associated hardware interface and is therefore always up.

    One use of such an interface is to simply assign an IP address to the router as a whole rather than to a specific hardware interface.

    This allows the assigned IP address to be used to access the router, for example, Telnet, regardless of which real interfaces are up or down.

    Loopback interfaces are also used by some protocols.

    For example, the Loopback IP address can be used to assign the OSPF Router ID.

    There is no limit on the number of loopback interfaces you can create.

    Loopback interfaces do not have internal VLAN IDs or MAC addresses.

    With Layer 2 Cisco switches like the 3500XL or 2950, a loopback interface is not needed since these switches are not capable of routing between interfaces.

    The management VLAN of the switch acts like the loopback interface since they are both logical interfaces.

    When you have a Layer 3 switch like a Cisco Catalyst 3550 or 3750, to configure a loopback interface from the config mode, complete these steps:

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    beigemonkey

    That's not what I am looking for. I have a issue with request coming from inside the network is not able to hit the inside server once it goes outside the network.

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    0 Votes
    David-123

    A loopback interface is generally used by routers or Layer 3 capable switches so that they have a reliable IP interface for routing updates.

    In other words, a loopback interface is a special virtual interface created in software.

    It has no associated hardware interface and is therefore always up.

    One use of such an interface is to simply assign an IP address to the router as a whole rather than to a specific hardware interface.

    This allows the assigned IP address to be used to access the router, for example, Telnet, regardless of which real interfaces are up or down.

    Loopback interfaces are also used by some protocols.

    For example, the Loopback IP address can be used to assign the OSPF Router ID.

    There is no limit on the number of loopback interfaces you can create.

    Loopback interfaces do not have internal VLAN IDs or MAC addresses.

    With Layer 2 Cisco switches like the 3500XL or 2950, a loopback interface is not needed since these switches are not capable of routing between interfaces.

    The management VLAN of the switch acts like the loopback interface since they are both logical interfaces.

    When you have a Layer 3 switch like a Cisco Catalyst 3550 or 3750, to configure a loopback interface from the config mode, complete these steps:

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    0 Votes
    beigemonkey

    That's not what I am looking for. I have a issue with request coming from inside the network is not able to hit the inside server once it goes outside the network.