Documentation > Userspace Application Arguments > --eamt
--eamt
Index
Description
Interacts with Jool’s Explicit Address Mapping Table (EAMT). See the introduction for a swift overview, our RFC summary for more details, or the EAM RFC for the full story.
Syntax
jool_siit --eamt (
[--display] [--csv]
| --count
| --add <IPv4-prefix> <IPv6-prefix> [--force]
| --remove <IPv4-prefix> <IPv6-prefix>
| --flush
)
Arguments
Operations
--display
: The EAMT is printed in standard output. This is the default operation.--count
: The number of entries in the EAMT are printed in standard output.--add
: Combines<IPv4-prefix>
and<IPv6-prefix>
into an EAM entry, and uploads it to Jool’s table.--remove
: Deletes from the table the EAM entry described by<IPv4-prefix>
and/or<IPv6-prefix>
.--flush
: Removes all entries from the table.
Options
Flag | Description |
--csv |
Print the table in Comma/Character-Separated Values format. This is intended to be redirected into a .csv file. |
--force |
Upload the entry even if overlapping occurs (See the next section). |
Overlapping EAM entries
By default, EAMT entries are not allowed to overlap. You can use --force
while --add
ing to override this property. When overlapping EAMT entries exist, Jool picks based on longest match prefix.
For example:
IPv4 Prefix | IPv6 Prefix |
---|---|
192.0.2.0/24 | 2001:db8:aaaa::/120 |
192.0.2.8/29 | 2001:db8:bbbb::/125 |
Address 192.0.2.9
matches 192.0.2.8/29
better than 192.0.2.0/24
, so it will get translated as 2001:db8:bbbb::1
, not 2001:db8:aaaa::9
.
Notice this creates assymetry. 2001:db8:aaaa::9
gets translated as 192.0.2.9
, which in turn gets translated as 2001:db8:bbbb::1
. Depending on your use case, this can break communication.
Overlapping EAMT entries exist to help EAM coexist with IVI. Other use cases might arise in the future.
Examples
Add a handful of mappings:
# jool_siit --eamt --add 192.0.2.1 2001:db8:aaaa::
# jool_siit --eamt --add 192.0.2.2/32 2001:db8:bbbb::b/128
# jool_siit --eamt --add 192.0.2.16/28 2001:db8:cccc::/124
# jool_siit --eamt --add 192.0.2.128/26 2001:db8:dddd::/64
# jool_siit --eamt --add 192.0.2.192/31 64:ff9b::/127
Display the new table:
$ jool_siit --eamt --display
64:ff9b::/127 - 192.0.2.192/31
2001:db8:dddd::/64 - 192.0.2.128/26
2001:db8:cccc::/124 - 192.0.2.16/28
2001:db8:bbbb::b/128 - 192.0.2.2/32
2001:db8:aaaa::/128 - 192.0.2.1/32
(Fetched 5 entries.)
Dump the database on a CSV file:
$ jool_siit --eamt --display --csv > eamt.csv
Display the number of entries in the table:
$ jool_siit --eamt --count
5
Remove the first entry:
# jool_siit --eamt --remove 2001:db8:aaaa::
Empty the table:
# jool_siit --eamt --flush