[Xorp-hackers] PIM-SM4: Cand-RP and Cand-BSR Inconsistency

[Pavlin Radoslavov]

Samuel Lucas Vaz de Mello <samuellucas at datacom.ind.br> wrote:

> Hi!
> 
> I'm playing around with pimsm4 and found a strange behavior that seems to be a bug.
> 
> To reproduce it, first add a cand-rp for any group-prefix and commit. Then, add a cand-bsr for the same group-prefix. When trying to commit I got the following error:
> 
> 102 Command failed Cannot add configure BSR with vif eth0 address 10.1.3.11 for zone 224.0.0.0/4(non-scoped): already have scope zone 224.0.0.0/4(non-scoped)
> 
> =================================================
> samuellucas at erdinger# set protocols pimsm4 bootstrap cand-rp group-prefix 224.0.0.0/4 cand-rp-by-vif-name eth0
> [edit]
> samuellucas at erdinger# commit
> OK
> [edit]
> samuellucas at erdinger# set protocols pimsm4 bootstrap cand-bsr scope-zone 224.0.0.0/4 cand-bsr-by-vif-name eth0
> [edit]
> samuellucas at erdinger# commit
> Commit Failed
> 102 Command failed Cannot add configure BSR with vif eth0 address 10.1.3.11 for zone 224.0.0.0/4(non-scoped): already have scope zone 224.0.0.0/4(non-scoped)[edit]
> samuellucas at erdinger# 
> ==================================================

I need to double-check with the PIM BSR spec, but I think that
224.0.0.0/4 has special meaning (it is the "global" zone) and cannot
be configured as a scoped zone.
Hence, the behavior is correct, though the error could be more user
friendly.

If you think the above statement is incorrect, then please submit a
Bugzilla entry about the issue. For the time being no need to write
a patch, until we know it is actually a bug :)

Thanks,
Pavlin

> In the code I found that PimNode::add_config_cand_rp adds a BSR zone when adding the RP and add_config_cand_bsr fails when finds this added zone. Also, this zone is not visible in the configuration tree (otherwise xorpsh/rtrmgr would have handled this as a modification in a existing cand-bsr, which works fine).
> 
> I'm wondering what would be the best way to handle this. 
> There are a few options: We can replace the automatically created zone with the user provided one, we can report the zone to rtrmgr/xorpsh or we can reuse the created zone and merge the changes, if possible.
> 
> What do you recommend?
> 
> 
> BTW, after writing a patch how do I submit it? Just mail it to this list?
> 
> 
> Thank you,
> 
>  - Samuel
> 
> 
> 
> 
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