the fs_ckpt fsname -l -a is listing you all existing checkpoints of a FS.
The ip-replication is based on two checkpoints, they are refreshed round robin.
fs_ckpt is listing the creation time of the checkpoints, while the ls -l is giving the name based on the last uptime.
With a running ip-replication. fs_ckpt fsname -l -a will list the 2 replication checkpoints and your custom created ones.
To determine, which of the 2 replication checkpoints is which mountpoint is a bit tricky. But as they should not be used by anything else than the ip-replication itself, it shouldn´t matter which one is which one.