TechSpot

LAN servers restricted to LAN server (class c)

By kmm93
Dec 18, 2011
Post New Reply
  1. When I connect to a server added to my favorites it gives me this error
    "lan servers restricted to lan server(class c)"...

    Can some one help me out?
     
  2. jobeard

    jobeard TS Ambassador Posts: 13,446   +324

    There are a coulple of IP Network Classes, which define the range of the first number in the address and the value used as the Netmask.

    On our LAN connections, we need to use a Private, non-routing IP address of Class {A,B,C}. The Private, non-routing means that there are thousands of duplicates in the world but it doesn't matter as the Internet will never route to one of these directly - - that's the job of the router with NAT that has a lan with systems on these addresses.

    The Class {A,B,C} can be seen/defined
    in this Wiki article


    Code:
    Historical classful network architecture
    Class	Leading bits   Range of first octet 	  Network portion   Host portion Number of networks  Number of addresses per network
    A		0	     0 - 127		  a	  		b.c.d	    2^7 = 128		2^24 = 16777216
    B		10	    128–191		  a.b	  		c.d	    2^14 = 16384	2^16 = 65536
    C		110	    192–223		  a.b.c	  		d	    2^21 = 2097152	2^8 = 256
    
    and that means {if the message is correct} that your lan IP addresses should look like 192.x.y.z

    I am puzzled by your description and guess that your existing ip address is not 192.* - - get a command prompt and enter IPCONFIG
    you should see something like
    Code:
    Ethernet adapter Local Area Connection:
    
            Connection-specific DNS Suffix  . : rr.com
            IP Address. . . . . . . . . . . . : 192.168.0.4
            Subnet Mask . . . . . . . . . . . : 255.255.255.0
            Default Gateway . . . . . . . . . : 192.168.0.1
    report your findings . . .
     
  3. kmm93

    kmm93 TS Rookie Topic Starter Posts: 20

    Well I have uploaded the description.

    I hope it helps..
     

    Attached Files:

  4. jobeard

    jobeard TS Ambassador Posts: 13,446   +324

    ok, that is the problem - - -
    Code:
    Ethernet adapter Local Area Connection:
            Connection-specific DNS Suffix  . : logondhcp.net.pk
            IP Address. . . . . . .[B]192.168.86.178[/B]<valid Class C 
            Subnet Mask . . . . .255.255.240.0  <unusual mask, but valid
            Default Gateway . .:                           <invalid
    
    PPP adapter Broadband Connection:
            Connection-specific DNS Suffix  . :
            IP Address. . . . . . . 172.16.9.31        <valid Class B
            Subnet Mask . . . . . 255.255.255.255  <very narrow mask (ie only one address allowed)
            Default Gateway . . 172.16.9.31        <valid gateway but points to itself (ie not very useful)
    
    I believe you are on a DSL connection (hense the PPP connection).
    The PPP will not normally route to your Ethernet, due to different gateway addresses.

    Get the command prompt again and enter ROUTE PRINT >myRoutes.txt

    it should look something like
    Code:
    C:\Documents and Settings\Jeff>route print
    ===========================================================================
    Interface List
    0x1 ........................... MS TCP Loopback interface
    0x2 ...00 0f b0 3d bc 1d ...... Realtek RTL8139 Family PCI Fast Ethernet NIC - Packet Scheduler Miniport
    ================================================================
    ==========================================================
    Active Routes:
    Network Destination        Netmask          Gateway       Interface  Metric
              0.0.0.0          0.0.0.0      192.168.0.1     192.168.0.4       20
            127.0.0.0        255.0.0.0        127.0.0.1       127.0.0.1       1
          192.168.0.0    255.255.255.0      192.168.0.4     192.168.0.4       20
          192.168.0.4  255.255.255.255        127.0.0.1       127.0.0.1       20
        192.168.0.255  255.255.255.255      192.168.0.4     192.168.0.4       20
            224.0.0.0        240.0.0.0      192.168.0.4     192.168.0.4       20
      255.255.255.255  255.255.255.255      192.168.0.4     192.168.0.4       1
    Default Gateway:       192.168.0.1
    ===============================================================
    Persistent Routes:
      None
    
     
  5. kmm93

    kmm93 TS Rookie Topic Starter Posts: 20

    Well i do not use DSL internet but moreover a broadband connection based on sharing.

    By the way here are the details.
     

    Attached Files:

  6. jobeard

    jobeard TS Ambassador Posts: 13,446   +324

    Hmm; btw- Broadband includes DLS, Cable and Satellite connections to an ISP.

    I don't understand what you mean by 'based on sharing'.
    Typically our networks are wired thusly:
    Code:
    ISP- - modem---router---multiple.systems
    and the sharing is achieved via the router NAT support to your ISP connection.
    A server would just be another ethernet connection to the router.

    By broadband connection based on sharing, do you mean something like:
    Code:
      router---some.systemA - - - server
    I'm seeing really strange stuff in the routing table.
    [​IMG]
    Column 1 are line numbers for discussion.

    lines 1-5 are very normal and are the primary connection to the internet
    (as verified by line 1 Network Dest = 0.0.0.0 and line 12 at the bottom.
    These two say any inputs or outputs default to this connection.

    All the other stuff is questionable.

    Line 6: is suspicious: It is frequently associated with virus's and trojans:
    NetRange: 1.0.0.0 - 1.255.255.255
    CIDR: 1.0.0.0/8
    NetName: APNIC-1
    NetHandle: NET-1-0-0-0-1
    OrgName: Asia Pacific Network Information Centre
    OrgId: APNIC
    City: Milton
    StateProv: QLD
    Country: AU​

    Lines 7-11 are the Class B address that is causing the diagnostic message.

    SO. HOW ARE YOU CREATING THIS CONNECTION?
    Is this a VPN connection?

    I would bet you have Internet access as long as the 192.168.86.178 connection does not exist.
    IMO, the Default Gatway is being changed whe you make this connection.
     
  7. kmm93

    kmm93 TS Rookie Topic Starter Posts: 20

    Well I am taking a connection from a ISP. He has placed a device at the top floor of our building. From there connection is distributed to different flats through wires.

    But I think this problem is telling me of a problem in cs folder not in the internet connection.
    Well this did not happen first but have generated in the past few days which further confirms the related thing causing it.

    "Lan servers are restricted to local clients (class c)", this is the problem that has worried me, but don't know WHY?
     
  8. jobeard

    jobeard TS Ambassador Posts: 13,446   +324

    huh? What's that?
    come on! Routing table is a mess
    and you don't have the gateway correct
    and an entry that shouts VIRUS.

    I guess all the above was of no interest or help - - too bad

    It's your system.

    I would be looking into the Virus/Malware Forum for tools to verify your system is clean.
     
  9. kmm93

    kmm93 TS Rookie Topic Starter Posts: 20

    I dont know how but now the error has disappeared and I can easily connect to the server.
    YEAHH!!!!

    By the way thanks for your help,

    Regards,
    Khawaja Mustafa
     
  10. jobeard

    jobeard TS Ambassador Posts: 13,446   +324

    Wonderful - - thanks for the feedback :)
     
  11. ---agissi---

    ---agissi--- TechSpot Paladin Posts: 2,384   +15

    Very through explanation Jobeard, however I think it came off a bit technical as it was directly to the point and T. I appreciated it.
     
     


Add New Comment

TechSpot Members
Login or sign up for free,
it takes about 30 seconds.
You may also...


Get complete access to the TechSpot community. Join thousands of technology enthusiasts that contribute and share knowledge in our forum. Get a private inbox, upload your own photo gallery and more.