ProxySG appends "www." and "com" in the DNS query on plain hostname.

Products

• ProxySG Software - SGOS

Issue/Introduction

When an explicit client sends a DNS query to ProxySG using a plain hostname, eg "spektrum" the ProxySG will compose and send a second query for "www.spektrum.com".

Environment

Explicit ProxySG deployment.

Cause

The command responsible for sending the secondary query is "http www-redirect" in the conf t mode. In the event of a failed DNS lookup for the plain hostname the ProxySG will impute "www." and ".com" onto the host name. It will perform a DNS lookup on that construction and if successful, will return the imputed name in an HTTP 302 Found response (URL redirection).

Original DNS query:
Domain Name System (query)
    [Response In: 2295]
    Transaction ID: 0x7c6d
    Flags: 0x0100 Standard query
    Questions: 1
    Answer RRs: 0
    Authority RRs: 0
    Additional RRs: 0
    Queries
        spectrum: type A, class IN
            Name: spectrum
            [Name Length: 8]
            [Label Count: 1]
            Type: A (Host Address) (1)
            Class: IN (0x0001)

DNS response: Server Failure
Domain Name System (response)
    [Request In: 2294]
    [Time: 0.000458000 seconds]
    Transaction ID: 0x7c6d
    Flags: 0x8182 Standard query response, Server failure
    Questions: 1
    Answer RRs: 0
    Authority RRs: 0
    Additional RRs: 0
    Queries
        spectrum: type A, class IN
            Name: spectrum
            [Name Length: 8]
            [Label Count: 1]
            Type: A (Host Address) (1)
            Class: IN (0x0001)
 

OR

DNS response: No such name
Domain Name System (response)
    [Request In: 940]
    [Time: 0.000657000 seconds]
    Transaction ID: 0x3267
    Flags: 0x8183 Standard query response, No such name
    Questions: 1
    Answer RRs: 0
    Authority RRs: 1
    Additional RRs: 0
    Queries
        spektrum: type A, class IN
            Name: spektrum
            [Name Length: 8]
            [Label Count: 1]
            Type: A (Host Address) (1)
            Class: IN (0x0001)
    Authoritative nameservers

Second DNS query:
Domain Name System (query)
    [Response In: 943]
    Transaction ID: 0xba53
    Flags: 0x0100 Standard query
    Questions: 1
    Answer RRs: 0
    Authority RRs: 0
    Additional RRs: 0
    Queries
        www.spektrum.com: type A, class IN
            Name: www.spektrum.com
            [Name Length: 16]
            [Label Count: 3]
            Type: A (Host Address) (1)
            Class: IN (0x0001)



 

Resolution

If you do not wish to see this behavior for security reasons run this command in the conf t mode

http no www-redirect