APRICOT 2006 at Perth Western Australia APRICOT 2006 at Perth Western Australia I P addressing Design in Practice Design in Practice I P addressing Akinori MAEMURA < maem@maem.org> Masataka MAWATARI < mawatari@dti.ad.jp> Kiyoteru I SHI HARA < ki-ishihara@kddi.com>
APRI COT 2006 APRI COT 2006 What we will talk here from now on What we will talk here from now on � I P Address � I P Addressing ing is one of the components is one of the components of of network design design network – I t' 's basic to networking, but really important, and not easy – K Know now - -how is not how is not shared shared enough, enough, is it? is it? – � Here will be presented about – Practical and current I Pv4 Addressing Practical and current I Pv4 Addressing – – I Pv6 I Pv6 Addressing in comparison with I Pv4 Addressing in comparison with I Pv4 – 2 2
I Pv4 Addressing Addressing I Pv4 which we should have been familiar with… … which we should have been familiar with
APRI COT 2006 APRI COT 2006 Addressing Plan is like… … Addressing Plan is like � Segment and reserve address block for � Segment and reserve address block for several attributes several attributes • by by link category link category (user address (user address pool pool, backbone , backbone • link, loopback addresses … …etc) etc) link, loopback addresses • by service (broadband, dialup by service (broadband, dialup … …etc) etc) • • by by geographical/ topological area geographical/ topological area • BackBone BackBone / 15 / 15 / 17 / 17 / 18 / 18 / 18 / 18 / 18 / 17 / 17 / 18 4 4
APRI COT 2006 APRI COT 2006 But reality is… … But reality is � Addressing plan needs to be fit as increase of users � Addressing plan needs to be fit as increase of users and services and services – Not easy to operate as planned. Not easy to operate as planned. – – Reality is often very different from the assumption Reality is often very different from the assumption – � Not easy to change design while operating. � Not easy to change design while operating. – We often have very little spare I P address for change We often have very little spare I P address for change – operations operations � I P address management starts getting disordered � I P address management starts getting disordered � An unnecessary loss is generated. � An unnecessary loss is generated. – I t gets more trouble some to make sure routing works I t gets more trouble some to make sure routing works – fine. . fine – Configuring ACL becomes Configuring ACL becomes more more difficult. difficult. – 5 5
APRI COT 2006 APRI COT 2006 Reduce the present problem. . Reduce the present problem � Renumbering -> Aggregation / 16 / 16 / 19 / 19 / 19 / 19 / 18 / 18 / 19 / 19 / 19 / 18 / 18 / 19 6 6
APRI COT 2006 APRI COT 2006 How we can do that? How we can do that? � Revisiting the addressing plan � Revisiting the addressing plan – Situations differs by each xSPs Situations differs by each xSPs – • Consumer I SP Consumer I SP • – The biggest The biggest block blocks s are are assigned for assigned for the client address pool the client address pool – • iDC iDC • – Fixed address Fixed address or address blocks or address blocks is assigned is assigned to to customers. customers. – • Leased Line Service Leased Line Service • – Various size of address block are connected to Access Various size of address block are connected to Access – Routers Routers – The The later to fix it, the more difficult to later to fix it, the more difficult to improve improve the the – order order • The availability of I P address The availability of I P address is is always changing. always changing. • • The situation of service The situation of service is is always changing, too. always changing, too. • 7 7
APRI COT 2006 APRI COT 2006 One of methods… … One of methods � I nitial Condition � I nitial Condition Broadband Broadband Access Servers Access Servers Access Provider's Access Provider's / 26 / 26 I SP's Router I SP's Router Router Router / 26 / 26 / 26 / 26 route * * * .* * * .1.0/ 26 next-hop * * * .* * * .* * * .* * * route * * * .* * * .1.64/ 26 next-hop * * * .* * * .* * * .* * * route * * * .* * * .1.128/ 26 next-hop * * * .* * * .* * * .* * * Pool Pool Address Address static routes static routes Blocks Blocks 8 8
APRI COT 2006 APRI COT 2006 One of methods… …(cont.) (cont.) One of methods � Users � Users increasing increasing… … Broadband Broadband Access Servers Access Servers Access Provider's Access Provider's / 26+ / 26 / 26+ / 26 I SP's Router I SP's Router Router Router / 26+ / 26 / 26+ / 26 / 26+ / 26 / 26+ / 26 route * * * .* * * .1.0/ 26 next-hop * * * .* * * .* * * .* * * route * * * .* * * .1.64/ 26 next-hop * * * .* * * .* * * .* * * route * * * .* * * .1.128/ 26 next-hop * * * .* * * .* * * .* * * route * * * .* * * .1.192/ 26 next-hop * * * .* * * .* * * .* * * route * * * .* * * .2.0/ 26 next-hop * * * .* * * .* * * .* * * Add / 26 Add / 26 for pool for pool address address When static routes increases, When static routes increases, blocks. blocks. external routes increases too external routes increases too… … 9 9
APRI COT 2006 APRI COT 2006 One of methods… …(cont.) (cont.) One of methods � Renumbering!! � Renumbering!! Broadband Broadband Access Servers Access Servers Access Provider's Access Provider's / 24 / 24 I SP's Router I SP's Router Router Router / 24 / 24 / 24 / 24 route * * * .* * * .10.0/ 24 next-hop * * * .* * * .* * * .* * * route * * * .* * * .11.0/ 24 next-hop * * * .* * * .* * * .* * * route * * * .* * * .12.0/ 24 next-hop * * * .* * * .* * * .* * * Pool Pool Address Address Blocks are Blocks are Static routes are getting Static routes are getting getting getting simple!!! simple!!! simple!!! simple!!! 10 10
APRI COT 2006 APRI COT 2006 To change the address plan… … To change the address plan � Renumber, defragment and aggregate!! � Renumbering is painful, but… – Together with other maintenances • Redundant network configuration will help easier maintenance – I t's still very good to execute renumbering little by little. • We can sometimes have a sufficient margin for We can sometimes have a sufficient margin for • renumbering. Keep track of amount of available I P renumbering. Keep track of amount of available I P address! address! • Day Day- -to to- -day checks will work for planning tiny day checks will work for planning tiny • renumbering renumbering – I t will result in reducing the division loss of I P address. 11 11
APRI COT 2006 APRI COT 2006 Summary so far Summary so far � Your I Pv4 network is already rather old. � Your I Pv4 network is already rather old. – I t's necessary to review the I P address I t's necessary to review the I P address – design design • Clues Clues for the improvement may come out for the improvement may come out • although it is still not found. . although it is still not found – You still need to keep You still need to keep operati operating ng your your I Pv4 I Pv4 – network. network. � I Pv6 is coming ! I t is being as troublesome � I Pv6 is coming ! I t is being as troublesome as I Pv4 is now! as I Pv4 is now! – T Think about I Pv6 addressing hink about I Pv6 addressing now, and the now, and the – trouble will be less! trouble will be less! – Don Don' 't repeat the t repeat the same same mistake as mistake as I Pv4. I Pv4. – 12 12
ing I Pv6 I Pv6 Considering Consider
APRI COT 2006 APRI COT 2006 The way we consider about I Pv6 addressing The way we consider about I Pv6 addressing � Only dual stuck network is to be focused on � Do we need any special consideration on � Do we need any special consideration on I Pv4 I Pv4 addressing when I Pv6 is added on the network? addressing when I Pv6 is added on the network? � The method for transition of I Pv6 which you � The method for transition of I Pv6 which you suppose suppose – First, w First, w hile hile considering I Pv6 considering I Pv6 transition transition, , – improvement of I Pv4 network improvement of I Pv4 network – Secondly, Secondly, I ntroduction for I Pv6 I ntroduction for I Pv6 – • We would like to examine whether consideration We would like to examine whether consideration (1) (1) is is • necessary necessary I Pv4( now I Pv4( now ) ) I Pv4( I Pv4( improvement improvement) ) I Pv4/ I Pv6 I Pv4/ I Pv6 Care for I Pv6 I Pv6 introduction introduction I s necessary? Care for I s necessary? Which items we should care for? Which items we should care for? 14 14
APRI COT 2006 APRI COT 2006 I tems to be considered I tems to be considered � Addressing � Addressing – Link Links s – • Point Point- -to to- -Point Point Link Link • • LAN LAN segment segment • – Logical interface Logical interfaces s – � Area � Area segmentation segmentation of address block of address block � Router I D � Router I D � Renumbering � Renumbering 15 15
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