RE: RFC 1918 filtering on ISP Edge router

From: Jacques Eding (jacques@eding.org)
Date: Sun Apr 25 2004 - 15:49:25 GMT-3


Check this rfc,

ftp://ftp.rfc-editor.org/in-notes/rfc3330.txt

Jacques
ccnp/ccdp/ccisp

-----Original Message-----
    From: "Carlos Marchini"<cmarchini@signetdiagnostic.com>
    Sent: 25-4-04 20:27:18
    To: "annu_roopa@yahoo.com"<annu_roopa@yahoo.com>
    Cc: "ccielab@groupstudy.com"<ccielab@groupstudy.com>
    Subject: FW: RFC 1918 filtering on ISP Edge router
    
    If I am not mistaken they are talking about the 127.0.0.1 address or as
    Microsoft calls it localhost address. I don't know if the 169.0.254.0
    address is a Microsoft registered address. I think this is DHCP reserved
    address not specific to Microsoft.
    
    What I wonder is if we are supposed to block all the 127.0.0.0
    0.255.255.255 network or only the 127.0.0.1 0.0.0.0 address? And what
    does Cisco consider a Microsoft registered address. (Maybe both
    127.x.x.x and 169.0.254.x network)
    
    Does any one know a good Cisco link for this subject?
    
    Thanks,
    Carlos
    
    
    Annu Roopa wrote:
    
>Kenneth and group,
>
>Thanks to all who took time to answer and clarify my doubts. I have another
    Q on the same topic which went unanswered. I would like to know what are
    MSoft reserved addresses which i see keep getting mentioned in Documents and
    on Gstudy.
>
>I think the only reserved MS address is the one when IP does not get
    allocated to a MS device by DHCP and it chooses 169.0.254.1. Is this address
    right or are there ANY other addresses i should be aware of. Unfortuantely i
    am not very Msoft savvy but would be eager to know of any document or URL
    which discusses this.
>
>Thanks again,
>Annu
>
>
>
>Kenneth Wygand <KWygand@customonline.com> wrote:
>
>Anna,
>
>
>
>Please read below. All this information is in the original document,
    Router Security
>
>Configuration Guide published by SNAC and NSA. Id attach the document
    but Groupstudy doesnt accept attachments, so you can download the document
    from the following link:
>
>
>
>http://nsa2.www.conxion.com/cisco/download.htm
>
>
>
><snip>
>
>IP Address Spoof Protection
>
>The filtering suggestions in this sub-section are applicable to border
    routers, and most
>
>interior routers. With backbone routers, it is not always feasible to
    define inbound
>
>and outbound.
>
>Inbound Traffic
>
>Do not allow any inbound IP packet that contains an IP address from the
    internal
>
>network (e.g., 14.2.6.0), any local host address (1

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