8. Traces d'une ouverture de session PPPoE

Pour obtenir la trace des transactions entre les deux routeurs de la maquette, on fait appel à la commande journalctl et on consulte les journaux de l'unité systemd ajoutée sur chaque routeur.

8.1. Journaux du routeur Spoke

Côté routeur Spoke, l'unité systemd s'appelle ppp.service. Voici la commande de consultation de l'ouverture de session PPP la plus récente.

journalctl -n 100 -f -u ppp.service
spoke systemd[1]: Starting ppp.service - PPPoE Client Connection...
spoke pppd[629]: Plugin rp-pppoe.so loaded.
spoke pon[629]: Plugin rp-pppoe.so loaded.
spoke pppd[639]: pppd 2.5.0 started by root, uid 0
spoke systemd[1]: Started ppp.service - PPPoE Client Connection.
spoke pppd[639]: Send PPPOE Discovery V1T1 PADI session 0x0 length 121
spoke pppd[639]:  dst ff:ff:ff:ff:ff:ff  src b8:ad:ca:fe:00:06
spoke pppd[639]:  [service-name] [host-uniq 7f 02 00 00]
spoke pppd[639]: Recv PPPOE Discovery V1T1 PADO session 0x0 length 44
spoke pppd[639]:  dst b8:ad:ca:fe:00:06  src b8:ad:ca:fe:00:05
spoke pppd[639]:  [AC-name BRAS] [service-name] [AC-cookie eb 9f 92 61 e1 ee 01 a1 5d 8f 11 61 8a fb c8 4b fc 01 00 00] [host-uniq 7f 02 00 00]
spoke pppd[639]: Access-Concentrator: BRAS
spoke pppd[639]: Cookie: eb 9f 92 61 e1 ee 01 a1 5d 8f 11 61 8a fb c8 4b fc 01 00 00
spoke pppd[639]: AC-Ethernet-Address: b8:ad:ca:fe:00:05
spoke pppd[639]: --------------------------------------------------
spoke pppd[639]: Send PPPOE Discovery V1T1 PADR session 0x0 length 36
spoke pppd[639]:  dst b8:ad:ca:fe:00:05  src b8:ad:ca:fe:00:06
spoke pppd[639]:  [service-name] [host-uniq 7f 02 00 00] [AC-cookie eb 9f 92 61 e1 ee 01 a1 5d 8f 11 61 8a fb c8 4b fc 01 00 00]
spoke pppd[639]: Recv PPPOE Discovery V1T1 PADS session 0x1 length 12
spoke pppd[639]:  dst b8:ad:ca:fe:00:06  src b8:ad:ca:fe:00:05
spoke pppd[639]:  [service-name] [host-uniq 7f 02 00 00]
spoke pppd[639]: PPP session is 1
spoke pppd[639]: Connected to B8:AD:CA:FE:00:05 via interface enp0s1.441
spoke pppd[639]: using channel 1
spoke pppd[639]: Using interface ppp0
spoke pppd[639]: Connect: ppp0 <--> enp0s1.4412
spoke pppd[639]: sent [LCP ConfReq id=0x1 <mru 1492> <magic 0xbf826095>]
spoke pppd[639]: rcvd [LCP ConfReq id=0x1 <mru 1492> <auth eap> <magic 0x471e9bda>]
spoke pppd[639]: sent [LCP ConfAck id=0x1 <mru 1492> <auth eap> <magic 0x471e9bda>]
spoke pppd[639]: rcvd [LCP ConfAck id=0x1 <mru 1492> <magic 0xbf826095>]
spoke pppd[639]: sent [LCP EchoReq id=0x0 magic=0xbf826095]
spoke pppd[639]: rcvd [LCP EchoReq id=0x0 magic=0x471e9bda]
spoke pppd[639]: sent [LCP EchoRep id=0x0 magic=0xbf826095]
spoke pppd[639]: rcvd [EAP Request id=0xa1 Identity <Message "Name">]
spoke pppd[639]: EAP: Identity prompt "Name"
spoke pppd[639]: sent [EAP Response id=0xa1 Identity <Name "spoke_site0">]
spoke pppd[639]: rcvd [LCP EchoRep id=0x0 magic=0x471e9bda]
spoke pppd[639]: rcvd [EAP Request id=0xa2 MD5-Challenge <Value 81 3b a7 d1 eb 86 42 15 2c b9 1b 07 83 98 e2 dd b7 c6 57 b4 b5 0f> <Name "hub">]
spoke pppd[639]: sent [EAP Response id=0xa2 MD5-Challenge <Value 16 e7 3d fa d2 4b 6a 73 41 5f 86 c8 84 97 ed f0> <Name "spoke_site0">]
spoke pppd[639]: rcvd [EAP Success id=0xa3]
spoke pppd[639]: EAP authentication succeeded
spoke pppd[639]: peer from calling number B8:AD:CA:FE:00:05 authorized
spoke pppd[639]: sent [IPCP ConfReq id=0x1 <addr 0.0.0.0> <ms-dns1 0.0.0.0> <ms-dns2 0.0.0.0>]3
spoke pppd[639]: sent [IPV6CP ConfReq id=0x1 <addr fe80::9869:8831:104a:570a>]
spoke pppd[639]: rcvd [CCP ConfReq id=0x1 <bsd v1 15>]
spoke pppd[639]: sent [CCP ConfReq id=0x1]
spoke pppd[639]: sent [CCP ConfRej id=0x1 <bsd v1 15>]
spoke pppd[639]: rcvd [IPCP ConfReq id=0x1 <addr 10.4.41.1>]
spoke pppd[639]: sent [IPCP ConfAck id=0x1 <addr 10.4.41.1>]
spoke pppd[639]: rcvd [IPV6CP ConfReq id=0x1 <addr fe80::61d3:68e0:1e34:e123>]
spoke pppd[639]: sent [IPV6CP ConfAck id=0x1 <addr fe80::61d3:68e0:1e34:e123>]
spoke pppd[639]: rcvd [IPCP ConfNak id=0x1 <addr 10.4.41.2> <ms-dns1 172.16.0.2> <ms-dns2 172.16.0.2>]
spoke pppd[639]: sent [IPCP ConfReq id=0x2 <addr 10.4.41.2> <ms-dns1 172.16.0.2> <ms-dns2 172.16.0.2>]
spoke pppd[639]: rcvd [IPV6CP ConfAck id=0x1 <addr fe80::9869:8831:104a:570a>]
spoke pppd[639]: local  LL address fe80::9869:8831:104a:570a
spoke pppd[639]: remote LL address fe80::61d3:68e0:1e34:e123
spoke pppd[639]: Script /etc/ppp/ipv6-up started (pid 653)
spoke pppd[639]: rcvd [CCP ConfAck id=0x1]
spoke pppd[639]: rcvd [CCP ConfReq id=0x2]
spoke pppd[639]: sent [CCP ConfAck id=0x2]
spoke pppd[639]: rcvd [IPCP ConfAck id=0x2 <addr 10.4.41.2> <ms-dns1 172.16.0.2> <ms-dns2 172.16.0.2>]
spoke pppd[639]: Script /etc/ppp/ip-pre-up started (pid 658)
spoke pppd[639]: Script /etc/ppp/ip-pre-up finished (pid 658), status = 0x0
spoke pppd[639]: local  IP address 10.4.41.2
spoke pppd[639]: remote IP address 10.4.41.1
spoke pppd[639]: primary   DNS address 172.16.0.2
spoke pppd[639]: secondary DNS address 172.16.0.2
spoke pppd[639]: Script /etc/ppp/ip-up started (pid 662)
spoke pppd[639]: Script /etc/ppp/ipv6-up finished (pid 653), status = 0x0
spoke pppd[639]: Script /etc/ppp/ip-up finished (pid 662), status = 0x0

1

Sur un réseau de diffusion il est nécessaire d'identifier les deux hôtes qui doivent établir une session PPP. Cette toute première phase d'identification utilise des trames spécifiques avec les messages décrits dans la Section 1, « Interface Ethernet & protocole PPP ».

2

La sous-couche Link Control Protocol (LCP) assure la configuration automatique des interfaces à chaque extrémité. Les paramètres négociés entre les deux hôtes en communication sont multiples : l'adaptation de la taille de datagramme, les caractères d'échappement, les numéros magiques et la sélection des options d'authentification.

3

La sous-couche Network Control Protocol (NCP) assure l'encapsulation de multiples protocoles de la couche réseau. Dans l'exemple donné, c'est le protocole IPv4 qui est utilisé ; d'où l'acronyme IPCP.

8.2. Journaux du routeur Hub

Côté routeur hub, l'unité systemd s'appelle pppoe-server.service. Voici la commande de consultation de l'ouverture de session PPP la plus récente.

journalctl -n 100 -f -u pppoe-server.service
hub pppoe-server[610]: Session 1 created for client b8:ad:ca:fe:00:06 (10.4.41.2) on enp0s1.441 using Service-Name ''
hub pppd[610]: pppd 2.5.0 started by root, uid 0
hub pppd[610]: using channel 2
hub pppd[610]: Using interface ppp0
hub pppd[610]: Connect: ppp0 <--> /dev/pts/0
hub pppd[610]: rcvd [LCP ConfReq id=0x1 <mru 1492> <magic 0xbf826095>]
hub pppd[610]: sent [LCP ConfReq id=0x1 <mru 1492> <auth eap> <magic 0x471e9bda>]
hub pppd[610]: sent [LCP ConfAck id=0x1 <mru 1492> <magic 0xbf826095>]
hub pppd[610]: rcvd [LCP ConfAck id=0x1 <mru 1492> <auth eap> <magic 0x471e9bda>]
hub pppd[610]: sent [LCP EchoReq id=0x0 magic=0x471e9bda]
hub pppd[610]: sent [EAP Request id=0xa1 Identity <Message "Name">]
hub pppd[610]: rcvd [LCP EchoReq id=0x0 magic=0xbf826095]
hub pppd[610]: sent [LCP EchoRep id=0x0 magic=0x471e9bda]
hub pppd[610]: rcvd [LCP EchoRep id=0x0 magic=0xbf826095]
hub pppd[610]: rcvd [EAP Response id=0xa1 Identity <Name "spoke_site0">]
hub pppd[610]: EAP: unauthenticated peer name "spoke_site0"
hub pppd[610]: EAP id=0xa1 'Identify' -> 'MD5Chall'
hub pppd[610]: sent [EAP Request id=0xa2 MD5-Challenge <Value 81 3b a7 d1 eb 86 42 15 2c b9 1b 07 83 98 e2 dd b7 c6 57 b4 b5 0f> <Name "hub">]
hub pppd[610]: rcvd [EAP Response id=0xa2 MD5-Challenge <Value 16 e7 3d fa d2 4b 6a 73 41 5f 86 c8 84 97 ed f0> <Name "spoke_site0">]
hub pppd[610]: sent [EAP Success id=0xa3]
hub pppd[610]: peer from calling number b8:ad:ca:fe:00:06 authorized
hub pppd[610]: sent [CCP ConfReq id=0x1 <bsd v1 15>]
hub pppd[610]: sent [IPCP ConfReq id=0x1 <addr 10.4.41.1>]
hub pppd[610]: sent [IPV6CP ConfReq id=0x1 <addr fe80::61d3:68e0:1e34:e123>]
hub pppd[610]: EAP id=0xa3 'MD5Chall' -> 'Open'
hub pppd[610]: rcvd [IPCP ConfReq id=0x1 <addr 0.0.0.0> <ms-dns1 0.0.0.0> <ms-dns2 0.0.0.0>]
hub pppd[610]: sent [IPCP ConfNak id=0x1 <addr 10.4.41.2> <ms-dns1 172.16.0.2> <ms-dns2 172.16.0.2>]
hub pppd[610]: rcvd [IPV6CP ConfReq id=0x1 <addr fe80::9869:8831:104a:570a>]
hub pppd[610]: sent [IPV6CP ConfAck id=0x1 <addr fe80::9869:8831:104a:570a>]
hub pppd[610]: rcvd [CCP ConfReq id=0x1]
hub pppd[610]: sent [CCP ConfAck id=0x1]
hub pppd[610]: rcvd [CCP ConfRej id=0x1 <bsd v1 15>]
hub pppd[610]: sent [CCP ConfReq id=0x2]
hub pppd[610]: rcvd [IPCP ConfAck id=0x1 <addr 10.4.41.1>]
hub pppd[610]: rcvd [IPV6CP ConfAck id=0x1 <addr fe80::61d3:68e0:1e34:e123>]
hub pppd[610]: local  LL address fe80::61d3:68e0:1e34:e123
hub pppd[610]: remote LL address fe80::9869:8831:104a:570a
hub pppd[610]: Script /etc/ppp/ipv6-up started (pid 616)
hub pppd[610]: rcvd [IPCP ConfReq id=0x2 <addr 10.4.41.2> <ms-dns1 172.16.0.2> <ms-dns2 172.16.0.2>]
hub pppd[610]: sent [IPCP ConfAck id=0x2 <addr 10.4.41.2> <ms-dns1 172.16.0.2> <ms-dns2 172.16.0.2>]
hub pppd[610]: Script /etc/ppp/ip-pre-up started (pid 619)
hub pppd[610]: Script /etc/ppp/ip-pre-up finished (pid 619), status = 0x0
hub pppd[610]: local  IP address 10.4.41.1
hub pppd[610]: remote IP address 10.4.41.2
hub pppd[610]: Script /etc/ppp/ip-up started (pid 623)
hub pppd[610]: Script /etc/ppp/ipv6-up finished (pid 616), status = 0x0
hub pppd[610]: rcvd [CCP ConfAck id=0x2]
hub pppd[610]: Script /etc/ppp/ip-up finished (pid 623), status = 0x0