Re: IGMP Non Querier - Querier Transition

Thanks for the reply.
But I do not understand the intention of adopting query interval and
robustness value from the querier.

I guess that it adopts values from the Querier so that the NonQuerier should
continue with the adopted values so as to avoid any change because of down
of current querier.

Please mail me your analysis on this.

Thanks,
RajaSekhar

On Wed, Nov 11, 2009 at 12:13 PM, Indranil Bhattacharya <
[email protected]> wrote:

> Hi RajaSekhar,
>
>                      When a non-qurier becomes a querier, it should always
> use configured query interval and in absense of a configured value default
> should be used.
>
> Thanks,
> Indranil
>   On Tue, Nov 10, 2009 at 12:28 PM, rajasekar bonthala <
> [email protected]> wrote:
>
>>   RFC 3376 says that IGMP Non-Querier should adopt the robustness and
>> Query interval from the Querier.
>> Those sections are pasted below for reference.
>>
>> 4.1.6. QRV (Querier’s Robustness Variable)
>>
>> If non-zero, the QRV field contains the [Robustness Variable] value
>>
>> used by the querier, i.e., the sender of the Query. If the querier’s
>>
>> [Robustness Variable] exceeds 7, the maximum value of the QRV field,
>>
>> the QRV is set to zero. Routers adopt the QRV value from the most
>>
>> recently received Query as their own [Robustness Variable] value,
>>
>> unless that most recently received QRV was zero, in which case the
>>
>> receivers use the default [Robustness Variable] value specified in
>>
>> section 8.1 or a statically configured value.
>>
>> 4.1.7. QQIC (Querier’s Query Interval Code)
>>
>> The Querier’s Query Interval Code field specifies the [Query
>>
>> Interval] used by the querier. The actual interval, called the
>>
>> Querier’s Query Interval (QQI), is represented in units of seconds
>>
>> and is derived from the Querier’s Query Interval Code as follows:
>>
>> If QQIC < 128, QQI = QQIC
>>
>> If QQIC >= 128, QQIC represents a floating-point value as follows:
>>
>> 0 1 2 3 4 5 6 7
>>
>> +-+-+-+-+-+-+-+-+
>>
>> |1| exp | mant |
>>
>> +-+-+-+-+-+-+-+-+
>>
>> QQI = (mant | 0x10) << (exp + 3)
>>
>> Multicast routers that are not the current querier adopt the QQI
>>
>> value from the most recently received Query as their own [Query
>>
>> Interval] value, unless that most recently received QQI was zero, in
>>
>> which case the receiving routers use the default [Query Interval]
>> value specified in section 8.2.
>>
>>
>>
>>
>> The above sections says that these values need to adopted as their own
>> values.
>> But the RFC does not explain on whether the Non-Querier should continue
>> with the adopted values,when transitions to Querier state (if the existing
>> querier is down due to any reason).
>>
>> Can any one please clarify me on this.
>>
>> Thanks,
>> RajaSekhar
>>
>> _______________________________________________
>> magma mailing list
>> [email protected]
>> https://www.ietf.org/mailman/listinfo/magma
>>
>>
>

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