# Can't get LDAP replication working



## Irwin (May 5, 2015)

Hello everyone.

I am trying to setup LDAP replication between two nodes. After many days, I think I'm getting close (at least the servers connect to each other now). However, no replication is happening. In the logfile on the slave, I see:

```
May  5 15:16:12 i-ldap0 slapd[12965]: do_syncrep2: rid=001 cookie=csn=20150504163203Z#000000#00#000000,rid=001
May  5 15:16:12 i-ldap0 slapd[12965]: do_syncrep2: rid=001 CSN too old, ignoring 20150504163203.000000Z#000000#000#000000 (reqStart=20150504163203.000001Z,cn=accesslog)
```
I have checked the time on both servers and they seem to be OK. The master is an older version of openldap and I'm wondering if this could be the issue. Here is what I get from ContextCSN:

```
2015-05-05 12:29:39,913 - INFO : ContextCSN of ldaps://master : 20150505173840Z#000000#00#000000           OpenLDAP: slapd 2.3.42
2015-05-05 12:30:34,714 - INFO : ContextCSN of ldaps://slave  : 20150505173840.000000Z#000000#000#000000   OpenLDAP: slapd 2.4.40
```
The master has a "Z" in the 1st section and 0's in the 2nd. The slave has a period then a bunch of zeros followed by the "Z".

Is this a version thing or perhaps a time zone thing ?

Thank you,
Irwin


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## SirDice (May 6, 2015)

I'm not sure if this is due to the version differences. I've set up replication on LDAP before but this was always with two of the same versions. Is there any chance you can get both versions at the same level? Just to rule out any incompatibilities.


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## SirDice (May 6, 2015)

I did some digging for you but the format of ContextCSN did indeed change between 2.3 and 2.4. If I read things correctly a recent 2.4 _should_ be able to understand this and "do the right thing". So a 2.3 provider (aka 'master') should be able to replicate to a 2.4 consumer (aka 'slave'). The other way around however is not possible. So an N-Way Multi-Master setup is not possible with 2.3 and 2.4.


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## Irwin (May 6, 2015)

SirDice said:


> I did some digging for you but the format of ContextCSN did indeed change between 2.3 and 2.4. If I read things correctly a recent 2.4 _should_ be able to understand this and "do the right thing". So a 2.3 provider (aka 'master') should be able to replicate to a 2.4 consumer (aka 'slave')..



"Should" is the operative word here. Doesn't seem to be able to.

Since I can't upgrade the provider, I suppose I could install 2.3 on the consumer, assuming I can figure out how to download an older port.


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