# Weird behaviour of AX2500
**URL:** https://community.a10networks.com/t/weird-behaviour-of-ax2500/197
**Category:** System
**Created:** [February 6, 2013, 8:13am UTC](https://community.a10networks.com/t/weird-behaviour-of-ax2500/197 "2013-02-06T08:13:19Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@system](https://community.a10networks.com/u/system)
#### Post date: [February 6, 2013, 8:13am UTC](https://community.a10networks.com/t/weird-behaviour-of-ax2500/197/1 "2013-02-06T08:13:19Z")
```auto
I'm observing a weird behaviour on a pair of AX2500 running 2.6.1-P4:
When I do a HEAD request for say http://$VIRTIP/foo.html?$UNIQID the balancer gets the content
```
from one of the real servers and replies as expected. This works always without failures.
Now when a request for the same file is being done by one of Akamai’s CDN servers the balancer does not answer in the vast majority of requests.
Using tcpdump in front of the balancer and on the real servers I saw the incoming request, the balancer’s request to one of the real servers, the reply of the server but NO reply of the balancer to the requesting CDN server. Only about 10% of the requests are being served by the load balancer.
Btw - when changing the request type from HEAD to GET the requests are being served always.
Has anybody observed a similar problem or any idea what’s happening here?
Regards
Bjoern
---
### Author:  [@mischa](https://community.a10networks.com/u/mischa)
#### Post date: [February 6, 2013, 6:47pm UTC](https://community.a10networks.com/t/weird-behaviour-of-ax2500/197/2 "2013-02-06T18:47:03Z")
Is there any different in the actual request besides the HEAD or GET? Different HTTP version? Host header? etc…
---
### Author:  [@system](https://community.a10networks.com/u/system)
#### Post date: [February 7, 2013, 7:52am UTC](https://community.a10networks.com/t/weird-behaviour-of-ax2500/197/3 "2013-02-07T07:52:46Z")
No, the requests are identical . I copied the headers I saw in tcpdump and did the request mit netcat:
```auto
HEAD /foo/bar/baz.html?16359780648 HTTP/1.1
User-Agent: curl/7.15.5 (i386-redhat-linux-gnu) libcurl/7.15.5 OpenSSL/0.9.8b zlib/1.2.3 libidn/0.6.5
Accept: \*/\*
X-Akamai-CONFIG-LOG-DETAIL: true
```
TE: chunked;q=1.0
Connection: TE
Accept-Encoding: gzip
```auto
Akamai-Origin-Hop: 1
Via: 1.1 akamai.net(ghost) (AkamaiGHost)
X-Forwarded-For: 192.0.2.1
Host: www.example.com
Cache-Control: max-age=120
```
Connection: keep-alive
---
### Author:  [@mischa](https://community.a10networks.com/u/mischa)
#### Post date: [February 8, 2013, 9:27am UTC](https://community.a10networks.com/t/weird-behaviour-of-ax2500/197/4 "2013-02-08T09:27:50Z")
Let’s see if we can replicate the behaviour. I would also like to suggest to open a support case.
That way we can track the issue.