CCNA Video Training Series

Instant Access, Web or Mobile!

Only $99 for 30 days...
Renew at half price!

Buy/Renew

Includes FREE Practice Exams!

Member Login

Lost your password?

Not a member yet? Sign Up!

Official Lammle User Forum

Results 1 to 11 of 11

Thread: /32 Mask

  1. #1
    Join Date
    May 2008
    Posts
    4

    Default /32 Mask

    Dear All,

    Could anyone please explain me the use of /32 mask? When I connect to the Internet via my Mobile phone connected to Laptop (GPRS/EDGE), the following IP with /32 mask gets assigned:

    PPP adapter GPRS:

    Connection-specific DNS Suffix . :
    Description . . . . . . . . . . . : WAN (PPP/SLIP) Interface
    Physical Address. . . . . . . . . : 00-53-45-00-00-00
    Dhcp Enabled. . . . . . . . . . . : No
    IP Address. . . . . . . . . . . . : 10.189.10.173
    Subnet Mask . . . . . . . . . . . : 255.255.255.255
    Default Gateway . . . . . . . . . : 10.189.10.173

    Also the default gateway is same as my own address. Can anyone shed some light on the two points.

    Kind Regards,

    Obaid

  2. #2
    Join Date
    Mar 2008
    Posts
    2,888

    Default

    Can you reset the ip address?
    Also i see the DCHP is not enabled.

  3. #3
    Join Date
    May 2008
    Posts
    4

    Default /32 Mask

    Hello Big Evil,

    Here is the new IP assigned on my GPRS Dialup interface:

    PPP adapter GPRS:

    Connection-specific DNS Suffix . :
    Description . . . . . . . . . . . : WAN (PPP/SLIP) Interface
    Physical Address. . . . . . . . . : 00-53-45-00-00-00
    Dhcp Enabled. . . . . . . . . . . : No
    IP Address. . . . . . . . . . . . : 10.189.21.157
    Subnet Mask . . . . . . . . . . . : 255.255.255.255
    Default Gateway . . . . . . . . . : 10.189.21.157
    DNS Servers . . . . . . . . . . . : 221.132.112.8
    202.163.96.3
    NetBIOS over Tcpip. . . . . . . . : Disabled


    One thing I must tell you that everything is working fine. I mean the Internet via GPRS. I was curious about the /32 mask and the gateway address being the same as my IP@.

    BR,

    Obaid

  4. #4
    Join Date
    Mar 2008
    Posts
    2,888

    Default

    I am thinking that the /32 (255.255.255.25 5) would define a network of only one device.
    Also to the ip address and the default gateway being the same. Just one route.

  5. #5
    Join Date
    May 2008
    Posts
    4

    Default /32 Mask

    A network of one host, OK but how does it communicate with the hosts on the Internet?

    I am confused about this /32 concept. Can anyone please tell me the use ?

    BR,

    Obaid

  6. #6
    Join Date
    Dec 2006
    Posts
    2,191

    Default /32

    This is a weird output from PPP and it is never explained well.

    PPP, since it has to be point to point, places a route in your routing table of /32 meaning it is a host entry. "how do I get to this host?". Which is your next hop router.

    It really is an entry you can ignore. PPP places that in your routing table by default.

    Cheers!
    Todd

  7. #7
    Join Date
    Feb 2008
    Posts
    5

    Default

    Kind of an old post but so sorry but, a /32 mask is perfect when assigning loopback addresses as it really saves space. You can advertise the entire /24 address block and the have individual /32 addresses assigned to your loopbacks

  8. #8
    Join Date
    Nov 2008
    Location
    Birmingham, UK
    Posts
    1,425

    Default

    That's interesting actually because, technically, a subnet mask of /32 would define a single network address with no hosts. If a /31 defines a network address and it's broadcast address only, that would be the same as having one host (although not addressable). What the /32 netmask is saying is 'this host only'.

    Take a look at the routing table of a PC running Windows, netstat -r (or route print) will show you examples of /32 netmasks, and they are used to either define the host loopback address (turning the host address into 127.0.0.1) or to define broadcast addresses for the local LAN. Notice that for the latter, the default gateway is the same as the host address. As it is a local broadcast, no gateway is needed.
    CCNP R&S, CCNA DC
    Currently studying: CCIE R&S, CCNP Data Centre
    Follow my CCIE progress with study notes on my blog: http://beyondccna.blogspot.co.uk/

  9. #9
    Join Date
    Jun 2008
    Posts
    10

    Default a very basic thing to ask

    hi all,
    there is a very basic thing which what i want to ask:--
    difference between the switch, hub, repeater & bridge and especially with reference to the bandwidth.
    thnx

  10. #10
    Join Date
    Nov 2008
    Location
    Birmingham, UK
    Posts
    1,425

    Default

    CCNP R&S, CCNA DC
    Currently studying: CCIE R&S, CCNP Data Centre
    Follow my CCIE progress with study notes on my blog: http://beyondccna.blogspot.co.uk/

  11. #11
    Join Date
    Jun 2008
    Posts
    10

    Default

    thanks for your reply

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. CIDR or Subnet Mask?
    By tylerhen in forum CCENT Chapter 5: VLSM and Summarization
    Replies: 2
    Last Post: 11-13-2013, 06:39 AM
  2. Lab 10.1 Bad Mask
    By kam2700 in forum Chapter 12: Security
    Replies: 8
    Last Post: 12-07-2012, 10:57 PM
  3. Wildcard mask - how and why?
    By Big Evil in forum Announcements
    Replies: 0
    Last Post: 04-13-2011, 09:24 AM
  4. Subnet Mask
    By Rocha in forum Internetworking
    Replies: 5
    Last Post: 11-05-2009, 10:11 AM
  5. ACL wild mask
    By ngoni in forum Access Lists
    Replies: 3
    Last Post: 10-19-2009, 04:25 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •