[CentOS] Re: 4.5 upgrades on production servers?

[Dhawal Doshy]

Dhawal Doshy wrote:
> Scott Silva wrote:
>> Dhawal Doshy spake the following on 5/22/2007 9:25 AM:
>>> Scott Silva wrote:
>>>> Abba Communications spake the following on 5/21/2007 4:25 PM:
>>>>> Anyone besides me totally throw (most) caution into the wind and yum
>>>>> update
>>>>> any mission critical production 4.x boxen to 4.5 without any problems?
>>>>>
>>>>> 8-p
>>>>>
>>>>>  - rh
>>>> The only issues I am seeing are some snmp timeout errors in
>>>> MailScanner-mrtg.
>>> Scott,
>>>
>>> Did you manage to figure out an answer for this?
>> Not yet. I can poll snmp without error from the commandline, but get 
>> timeouts
>> almost every run of mailscanner-mrtg.
>> I am about ready to disable the snmp tests in mrtg until I can figure 
>> it out.
>> I am getting tired of having my servers nag me all day.
>>
>> Since you asked, are you seeing the same thing?
> 
> Yup, ever since servers upgraded to 4.5.. something like:
> 
> Timeout: No Response from localhost:161
> .
> 
> Works as expected from the command line though.

Further troubleshooting:
mailscanner-mrtg uses this to query the interfaces
/usr/bin/snmpwalk -v 2c -c COMMUNITY localhost:161 .1.3.6.1.2.1.2.2.1.16

This was timing out but would strangely not show on it on the terminal 
when run manually. This surely wasn't the case before.. so a 'rpm -q 
--changelog net-snmp-utils | head -13' tells me that now 'communication 
can be limited by tcp_wrappers'. Adding the right entry to hosts.allow 
appears to have solved the problem.