What is the difference between AXFR and Ixfr?
What is the difference between AXFR and Ixfr?
The current full zone transfer mechanism (AXFR) is not an efficient means to propagate changes to a small part of a zone, as it transfers the entire zone file. Incremental transfer (IXFR) as proposed is a more efficient mechanism, as it transfers only the changed portion(s) of a zone.
What is AXFR query?
AXFR is a protocol for “zone transfers” for replication of DNS data across multiple DNS servers. Unlike normal DNS queries that require the user to know some DNS information ahead of time, AXFR queries reveal resource records including subdomain names [1] .
What is a standard zone transfer in DNS?
Zone transfer is the process of copying the contents of the zone file on a primary DNS server to a secondary DNS server. Using zone transfer provides fault tolerance by synchronizing the zone file in a primary DNS server with the zone file in a secondary DNS server.
What are the three types of zone transfers?
There are three types of zone transfer to consider:
- Full zone transfer.
- Incremental zone transfer.
- AD replication.
How do you dig AXFR?
Initiating an AXFR zone-transfer request from a secondary server is as simple as using the following dig commands, where zonetransfer.me is the domain that we want to initiate a zone transfer for. First, we need to get the list of DNS servers for the domain: $ dig +short ns zonetransfer.me nsztm1. digi.
What port does AXFR use?
TCP port 53
The life cycle of an AXFR connection An AXFR connection may appear, at first glance, to be a typical TCP client-server connection: the AXFR client connects to an AXFR server on TCP port 53, sends an AXFR request, receives an AXFR response with the requested zone data, and closes the connection.
How do I prevent DNS zone transfer?
The simplest way to secure zone transfers is to restrict AXFR requests to trusted IP addresses. You can do it in your DNS server configuration or on your firewall. You can additionally use transaction signatures. Learn how to use transaction signatures in the BIND DNS server.
Is a DNS zone transfer illegal?
including the United States, it IS ILLEGAL to attempt unauthorized zone transfers.
Should DNSSEC be on or off?
If you’re running a website, especially one that handles user data, you’ll want to turn on DNSSEC to prevent any DNS attack vectors. There’s no downside to it, unless your DNS provider only offers it as a “premium” feature, like GoDaddy does.
Do we need DNSSEC?
The most typical attacks affecting websites without DNSSEC include but are not limited to DNS hijacking and DNS spoofing. Nowadays everybody needs DNSSEC. Assuming you’ve made up your mind to activate it, let’s see how it can be enabled for your domain name and DNS server.
What is the difference between IXFR and AXFR?
AXFR and IXFR is both the method of Zone Transfer. AXFR is the method synchronizing all of record in the zone, and IXFR records the previous zone transfer information in the journal file, referring to the journal file during zone transfer and transferring the incremental information.
When to use AXFR or IXFR in BIND9?
AXFR / IXFR can be specified when testing the zone transfer with the dig command. As mentioned above, there are AXFR (Full Zone Transfer) and IXFR (Differential Zone Transfer) for zone transfer, and basically IXFR (difference zone transfer) is set up by default in bind9, because default values of provide-ixfr and request-ixfr are “yes”.
How to initiate a DNS zone transfer ( AXFR )?
Initiating an AXFR zone-transfer request from a secondary server is as simple as using the following dig commands, where zonetransfer.me is the domain that we want to initiate a zone transfer for. First, we need to get the list of DNS servers for the domain: $ dig +short ns zonetransfer.me nsztm1.digi.ninja. nsztm2.digi.ninja.
Why does nslookup not return a valid answer?
This error commonly occurs with the ls and finger requests. The DNS name server found an internal inconsistency in its database and could not return a valid answer. The DNS name server refused to service the request. The DNS name server found that the request packet was not in the proper format. It may indicate an error in nslookup.