1Shane Kerr . RIPE 45, May 2003, Barcelona . http://www.ripe.net

Contact Data in the RIPE Database

Shane KerrRIPE NCC

<shane@ripe.net>

Shane Kerr . RIPE 45, May 2003, Barcelona . http://www.ripe.net 2

Background & Goal

• Certain kinds of data have caused problems– Domain objects (heavy use by ccTLD’s)– Person objects (heavy use by ccTLD’s, etc.)

• Cleanups have been made in the past– Consistency fixes– Deletions of unnecessary data, one-time and ongoing

• Small numbers of “inconsistencies” not a problem• Perform some measurement of data quality

Shane Kerr . RIPE 45, May 2003, Barcelona . http://www.ripe.net 3

Contact Data

• Contacts are:– Referenced by resources recorded in the Database– Administrative or technical

• Contacts have:– Name– Postal address– Phone number– E-mail address

Shane Kerr . RIPE 45, May 2003, Barcelona . http://www.ripe.net 4

Focus on e-mail

• Name impossible to check• Postal address/phone number difficult to check• E-mail possible

– Sadly optional for person objects

Shane Kerr . RIPE 45, May 2003, Barcelona . http://www.ripe.net 5

Checking the addresses

1. Unique e-mail extracted (about 500,000 in all)

2. Syntax check to remove garbage and bad TLD

3. Unique domains extracted (about 280,000 in all)

4. DNS checked• Algorithm from RFC 2821• MX lookups, with fallback to A lookups

5. SMTP checked• VRFY unreliable• Use RSET, MAIL, RCPT for each e-mail• Minimise connections (only 140,000 unique IP’s)

Shane Kerr . RIPE 45, May 2003, Barcelona . http://www.ripe.net 6

E-mail results

0%0% 7%3%

10%

80%

Bad Syntax

Bogus TLD

No DNS Entry

No Server

Server Refused

Okay

Shane Kerr . RIPE 45, May 2003, Barcelona . http://www.ripe.net 7

“Refusal” Codes

73%

9%

6%

4%

4%

1%

1%

2%

550: mailbox unavailable

553: mailbox name not allowed

452: insufficient system storage

451: local error in processing

554: transaction failed

421: service not available

551: user not local

all others

Shane Kerr . RIPE 45, May 2003, Barcelona . http://www.ripe.net 8

Interpreting the Results

• 20% of e-mail addresses can never be reached• 80% may still fail

– Depends on mail software and configuration– Impossible to check further without delivering mail– Even delivered mail may never be read

Shane Kerr . RIPE 45, May 2003, Barcelona . http://www.ripe.net 9

aut-num results

93%

1% 6% 0%

RIPE, reachable

non-RIPE, reachable

RIPE, unreachable

non-RIPE, unreachable

Shane Kerr . RIPE 45, May 2003, Barcelona . http://www.ripe.net 10

inetnum results

• A significant percentage of inetnum objects have no valid e-mail address.

• A much smaller percentage of actual IP addresses has no valid e-mail address, but still a significant amount.

• Most of these are because the “e-mail:” attribute is optional in the person object.

6%

23%

71%

4%

8%

88%

objects

IP addresses

reachable

non-reachable

no e-mail

Shane Kerr . RIPE 45, May 2003, Barcelona . http://www.ripe.net 11

Conclusions & Questions

• Many networks have no reachable contacts• “e-mail:” being optional is a significant reason• Is this a problem? If so, how big of a problem?• Possible actions:

– Make “e-mail:” mandatory– Check e-mail reachability on person creation/update– Put a “remark:” on networks with unreachable contacts– Return parent networks if contacts unreachable