Syslog ini selain bisa disimpan di local router, jg bisa dikirimkan ke Syslog server dengan menggunakan command,

logging a.b.c.d(alamat server)

Lalau traps apaan ?traps hampir sejenis dengan syslog, yaitu semacam notifikasi/warning. Bedanya,

1. Traps tdk muncul ke layar (pop up) ke layar console

2. Traps lebih variatif

3. Traps akan dikirimkan ke snmp server, baik dalam mode traps maupun inform

4. Traps adalah metoda yang digunakan pada snmp untuk mengirimkan secara aktif notifikasi ke snmp server

Kita bisa menggunakan snmp untuk men-traps kan(mengirimkan) syslog,

snmp-server enable traps syslog

snmp-server host 23.1.1.1 IPREAKMAN

dst,..

kutipan konfigurasi diatas artinya snmp akan mengcapture/mengkopi syslog yg biasa muncul di layar konsole dan mengirimkannya ke snmp server di alamat 23.1.1.1 dengan community IPFREAKMAN

Diketahui :

Clock rate  : DS3

Tc                : 10 ms

CIR             : 25 Mbps

Maka,

Clock rate Ds3 –> artinya interface akan mengirimkan data dengan kecepatan DS3, yaitu 45 Mbps. Tidak peduli berapapun nilai dari CIR ataupun BW yang diberikan oleh ISP

Dengan nilai Tc = 10 ms, maka nilai setiap Tc interface akan mengirimkan traffic sebanyak 45.000.000 x 0.01 = 450.000 bits

Sedangkan jatah yang diberikan ISP(CIR) adalah 25 Mbps, artinya setiap Tc ISP hanya mengijinkan 25.000.000 x 0.01 = 250.000 bits

–> terdapat selisih 200.000 bits !, jika Be is not allowed traffic akan di drop,

Untuk mengatasi ini, maka frame-relay harus men-shape/membuffer traffic yang akan dikirim !

Apa yang dilakukan oleh FR Traffic-Shaping(FRTS) ? FRTS tidak memperlambat kecepatan interface mengirimkan data, tp mem-buffer kelebihan data(200.000 bits) tersebut,

FR TS diaktifkan dengan meng-isu command frame-relay traffic shaping under interface/subinterface;

interface Serial0/0/0

frame-relay traffic-shaping

Hanya dengan meng-issue command tersebut, maka interface akan memberlakukan shaping pada default speed 56 Kbps,

Artinya setiap Tc kita akan mengirimkan data sebanyak 56.000 x 0.01 = 560 bits –> it’s getting worst !

Untuk itu, configure FRTS,

here’s the final solutions,

interface Serial 1/2

frame-relay class FRTS

frame-relay traffic-shaping

!

map-class frame-relay FRTS

frame-relay cir 25000000

frame-relay bc 250000

frame-relay be 200000

Setelah dipastikan bahwa multicast pada ISP beroperasi dengan baik, maka langkah kedua yang harus dilakukan adalah tunneling multicast dari client. Menurut sy metoda ini bisa disebut multicast over multicast, karena sbenarnya multicast traffic dari client dikirimkan dari suatu site ke site lainnya menggunakan multicast source and destination dari multicast ISP.

Pada topologi diatas, ISP support multicast, antara PE1 dan R3 dan PE2 dan R4 are multicast peering(Dense Mode),

Ketikan R3 mengenerate multicast traffic(Ping 227.7.7.7), PE 1 menerimanya. PE 1 segera membuat tunnel ke PE2 untuk mendeliver multicast source tersebut; ketika PE2 menerimanya, maka PE 2 akan segera meneruskannya ke R4 karena mereka berada dalam mode dense-mode.

Misalkan R2 ingin join multicast tersebut, maka R2 mengirimkan IGMP join messager ke PE2. Ketika PE2 menerima IGMP message tersebut, PE2 segera membuat tunnel ke R1 untuk mengirimkan IGMP join message.

Pada kondisi tersebut maka ada 2 tunnel antara PE1 dan PE2 yang ditujukan untuk menyalurkan traffic multicast dari PE1 ke PE2 dan yang satu lagi dari PE2 ke PE1.

Pertanyaannya, haruskah 2 tunnel??mengapa tidak cukup menggunakan satu tunnel saja?

sepertinya jawabannya adalah seperti ini,

Jika sy mengkonfigure secara manual tunnel antara PE1 dan PE2, maka sy cukup membuat satu tunnel saja yg sifatnya permanent. Ada atau tidak multicast packet, tunnel tersebut akan tetap eksis. Tunnel tersebut hanyalah tunnel GRE biasa yang digunakan untuk menyalurkan traffic dari R3 ke R4 dan sebaliknya,…bisa traffic apa saja, mulai dari IP, UDP, Mcast, dll

Jika tunnel ini dipublish ke IGP, maka tunnel tersebut akan berkompetisi dengan MPLS Backbone untuk dipilih sebagai best-path yang menghubungkan antara R3 dan R4. Kalo tdk mau hal ini terjadi, maka jgn publish tunnel tsb ke IGP, gunakan saja tunnel tsb untuk mcast sedangkan untuk traffic lainnya menggunakan MPLS BB

Nah, kl kita menginginkan tunnel tersebut secara otomatis terbangun, maka kita menggunakan MDT. Ketika ada mcast traffic dari R2 ke R4 MDT akan membuat 1 tunnel khusus utk menyalurkan traffic dari R2 ke R4, dan begitu pula sebaliknya.

Bagaimana caranya MDT membuat tunnel secara otomatis?

1. aktifkan mcast pada vrf

2. sertakan next-hop(loopback) dalam mcast

3. sertakan vrf interface dalam mcast

4. aktifkan mdt pada vrf

5. konfigurasi hal2 lainnya (RP, MA dll utk mcast client)

MDT menggunakan alamat mcast. Jadi jika sy meng-issue command “mdt default 239.100.100.100″ pada vrf; maka vrf akan mengenerate multicast group (*, 239.100.100.100) pada mroute ISP

Ketika R3 mengenerate mcast traffic, maka ISP akan segera memiliki routing table mroute (A, 239.100.100.100); dimana A adalah ip address of PE1. Artinya PE1 berkata “Hi, sy punya mcast traffic group 239.100.100.100 dengan alamat A”

Siapapun pada ISP yang memiliki (*, 239.100.100.100) pada mroute routing tablenya akan mendapatkan traffic mcast tersebut,

(*,G)/(*, 239.100.100.100)  : Sy ingin mendapatkan mcast traffic dari group 239.100.100.100

(S,G)/(A, 239.100.100.100) : Sy memiliki mcast traffic utk group 239.100.100.100 dgn alamat sumber adalah A. Siapapun yg ingin mendapatkan mcast traffic dari group 239.100.100.100 akan mendapatkan mcast traffic ini

Nah, isi mcast traffic tsb adalah mcast traffic dari VPN Client, makanny sy menyebut metoda ini mcast over mcast, wallahu’alam

semua informasi yg sy tuliskan disini adalah hasil pemahaman sy. bisa benar/bisa salah

Here’s the source,

http://fengnet.com/book/ios_mpls/ch05lev1sec1.html

By the time I read, I found a confusing statement,

The non-backbone areas, Area 1 and Area 2, are directly connected to the MPLS VPN superbackbone that functions as an OSPF Area 0. Therefore, an actual Area 0 is not required as in the traditional OSPF domain. Area 0 is a requirement only when the PE router is connected to two different non-backbone areas belonging to the same OSPF domain on a PE router.

It’s said that we will require an regular are 0 beside the Super-Backbone if the PE router is connected to two different non-backbone areas. I can understand it well,…and it seems that there’s somebody out there have the same problem with me,..

http://www.groupstudy.com/archives/ccielab/200911/msg00509.html

I have no idea whether it’s miss-type or there’s another good explanation for it,…

it seems that only two main steps to configure PPPoFR,
1. configure FR as ussual(p2p, p2mp, or hybrid)
2. run PPP on top of FR

The configuration is :

R0, R1 and R2 are connected to FR.SWITCH as the central

I used no “broadcast statement” in configuring the FR P2MP,

if)#frame relay map ip AA.BB.CC.DD XZY (without broadcast statement)

surely when i try to ping the broadcast address, it’s failed,

R0#ping
*Mar 1 00:33:40.131: %SYS-5-CONFIG_I: Configured from console by console255.255.255.255

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 255.255.255.255, timeout is 2 seconds:
…..

Then i activate the PPP,

first, configure interface virtual-template on both R1, and R2

second, apply it to interface DLCE that we want to,

here’s the final configuration of R1 and R2,

R1 :

interface Serial0/0
no ip address
encapsulation frame-relay
no arp frame-relay
no frame-relay inverse-arp
!
interface Serial0/0.1 multipoint
ip address 10.10.10.1 255.255.255.0
frame-relay map ip 10.10.10.2 102
frame-relay map ip 10.10.10.3 103
frame-relay interface-dlci 102 ppp Virtual-Template1
frame-relay interface-dlci 103 ppp Virtual-Template1
!
interface Serial0/1
no ip address
shutdown
serial restart-delay 0
!
interface Serial0/2
no ip address
shutdown
serial restart-delay 0
!
interface Serial0/3
no ip address
shutdown
serial restart-delay 0
!
interface Virtual-Template1
ip address 192.168.10.1 255.255.255.0

R2 :
!
interface Serial0/0
ip address 10.10.10.2 255.255.255.0
encapsulation frame-relay
serial restart-delay 0
no arp frame-relay
frame-relay map ip 10.10.10.1 201
frame-relay map ip 10.10.10.3 201
frame-relay interface-dlci 201 ppp Virtual-Template1
no frame-relay inverse-arp
!
interface Serial0/1
no ip address
shutdown
serial restart-delay 0
!
interface Serial0/2
no ip address
shutdown
serial restart-delay 0
!
interface Serial0/3
no ip address
shutdown
serial restart-delay 0
!
interface Virtual-Template1
ip address 192.168.10.2 255.255.255.0

Then try to ping the broadcast address from R1, here’s what i got…

R0#ping 255.255.255.255

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 255.255.255.255, timeout is 2 seconds:

Reply to request 0 from 192.168.10.2, 12 ms
Reply to request 1 from 192.168.10.2, 8 ms
Reply to request 2 from 192.168.10.2, 16 ms
Reply to request 3 from 192.168.10.2, 16 ms
Reply to request 4 from 192.168.10.2, 4 ms

it said that i got a reply from 192.168.10.2(virtual-template R2), but no reply from R3 since i configure no PPP over there,

Here’s what i can conclude,

PPPoFR is conditioned the FR network as a PPP network. Means that there will be a broadcast and features that’s available in PPP such as :

1. authentication (chap or pap)

2. network monitoring

3. quality ensuring

4. compression

5. etc

Here’ I wanna discuss about cell-mode MPLS.

There are two major tasks in configuring cell-mode,
1. Run an IGP inside the ATM Cloud
2. Activate label distribution

At the first time I learn about cell-mode ATM, the first task above make me confused(Run IGP).
The ATM devices those supported MPLS called LC-ATM(Label Control ATM), and an LC-ATM possibly
1. A Router that is support ATM interface and MPLS(c7200, c7500, etc)
2. An ATM Switch that is support MPLS(Lighstream 1010)

It’s a common thing to run IGP inside a Router, but it’s not in an ATM Switch. Yes, we may run IGP in Layer 3 Switch, but as I know ATM Switch cannot forward a packet based on IP destination, it’s switch the packet based on PVC. And when I continuing learn about ATM, I find the fact that ATM Switch have the ability to build the forwarding table like a Router.

Honestly I’ve no idea what actually an ATM Switch is,..what I know is only how it works,..
ATM Switch acts like a Router by building a forwarding-table, but it can not forward an IP packet; after all it’s a switch,…totally weird(for me)

Ok, what ever ATM Switch is live must go on,…

The second task in order to configure cell-mode MPLS is activate label distribution,

In a Router, this is done by two steps,
1. Create an LC subinterface
2. Activate label distribution protocol

!
interface ATM2/0/0
mtu 1500
no ip address

! interface ATM2/0/0.10 tag−switching
ip unnumbered Loopback0
tag−switching ip

In an ATM Switch, this is done by one step only,
1. Activate label distribution on ATM interace

! interface ATM12/0/0
ip unnumbered Loopback0
no ip directed−broadcast
tag−switching ip
!

To understand more about cell-mode MPLS, it’s nice to read this resources,
http://blog.ipexpert.com/?s=cell+mode+mpls
http://blog.ine.com/2008/07/10/cell-mode-mpls/

In ATM there’s a Label Control Protocol that’s by default using VCI 0/32 and VPI 1.
I don’t really understand what is Label Control Protocol, but it seems like a multicast 224.0.0.5 in OSPF network that’s used to exchange routing information. And we can change the Label Control Protocol from it’s default to any well known VPI VCI by using command ‘mpls atm control-vc‘, but remember that the ‘control-vc’ should be match in every peer.
By default ATM use only one VPI, that’s VPI 1. And we can configure how many VPI that can be used by using ‘mpls atm vpi start-vpi end-vpi‘

Pada konfigurasi diatas sw01, sw02, sw03 dan L3Switch adalah Router 3600 dengan menggunakan module NM-16ESW.

Karakteristik N-16ESW adalah murni layer 2, sehingga tidak akan bisa di-assign IP Address atau fitur layer 3 lainnya seperti NAT, routing, dll

Pembagian VLan,

VLan 2 : 10.1.2.0/24

VLan 3 : 10.1.3.0/24

VLan 4 : 10.1.10.0/24

VTP Mode,

sw01, sw02 dan sw03 = VTP mode Client

L3Switch = VTP mode server,

Pada GNS3, by default GNS3 akan mengembalikan flash to it’s default saat router di restart, sehingga bisa dipastikan konfigurasi vlan yang ada pada “flash:vlan.dat” akan hilang. Untuk itu, copy file vlan.dat ke nvram,

untuk memastikannya, lihat apakah ada file vlan.dat di nvram?

Resume konfigurasi,

• sw01, sw02, sw03 dan L3Switch berhubungan memlalui Trunk interface.
• L3Switch berperan sebagai VTP Server, dan switch lainnya sebagai client. Konfigurasi VLan cukup dilakukan di L3Switch(Server) yang kemudian akan diduplikasikan pada masing-masing VTP Client
• PC dan Switch berhubungan via access interface dan di-assign VLan number sesuai dengan design jaringan
• Pada jaringan VLan lalu lintas traffic dominan diatur oleh switch(Layer2), L3Switch baru akan bekerja jika dibutuhkan proses routing(Layer 3)
• Seluruh traffic yang berasal dari anggota VLan akan dan ditujukan ke anggota VLan akan diatur oleh Switch

Konfigurasi lengkap L3Switch,

L3Switch#sh run
Building configuration…

Current configuration : 2019 bytes
!
version 12.3
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname L3Switch
!
boot-start-marker
boot-end-marker
!
enable secret 5 $1$vUE3$LW.zkKo0GN6t6qWVF/zeT.
!
no aaa new-model
ip subnet-zero
!
!
no ip domain lookup
!
ip cef
!
interface FastEthernet0/0
switchport mode trunk
no ip address
!
.

.

!
interface FastEthernet0/15
no ip address
shutdown
!
interface Serial1/0
ip address 200.1.1.2 255.255.255.252
ip nat outside
serial restart-delay 0
no fair-queue
!
interface Serial1/1
no ip address
shutdown
serial restart-delay 0
!
interface Serial1/2
no ip address
shutdown
serial restart-delay 0
!
interface Serial1/3
no ip address
shutdown
serial restart-delay 0
!
interface Vlan1
no ip address
shutdown
!
interface Vlan2
ip address 10.1.2.1 255.255.255.0
ip nat inside
!
interface Vlan3
ip address 10.1.3.1 255.255.255.0
ip nat inside
!
interface Vlan10
ip address 10.1.10.1 255.255.255.0
ip nat inside
!
ip nat inside source list 10 interface Serial1/0 overload
ip http server
ip classless
ip route 0.0.0.0 0.0.0.0 200.1.1.1
!
!
access-list 10 permit 10.1.0.0 0.0.255.255
!
!
!
!
!
!
!
!
line con 0
line aux 0
line vty 0 4
password cisco
login
!
!
end

vtp bekerja dalam 3 mode,

• server(memiliki otoritas membuat vlan, dan penyebar vlan database)
• client(tidak memiliki otoritas untuk membuat vlan dan tunduk pada konfigurasi vtp server)
• transparant (pemberontak, akan mengacuhkan semua vtp message; tapi diteruskan)vpt mode server tidak akan meneruskan vtp messages ke tetangganya yang berbeda domain,

swo1[vtp mode : server][domain : tes] —–trunk—–sw02[vtp mode : server][domain : TES]—-trunk—–sw03[vtp mode : server][domain : tes]

pada kondisi diatas, vtp message dari sw01 diterima oleh sw02, namun tidak akan diteruskan ke sw03; karena berbeda domain.

vtp message akan diteruskan oleh sw02 jika,

• nama domain sama
• switch bekerja pada mode transparant

kesalahan umum pada vtp,

• revision number
• vtp domain/password
• jenis interface(vtp hanya akan melewati trunk interface)

konfigurasi vtp, seperti konfigurasi vlan pada umumnya disimpan di vlan.dat

Memories Of A Cisco Router

By Dan DiNicolo
Expert Author
Article Date: 2005-01-25

It may often seem like nothing more than a sleek metal box on the outside, but the internal memory components of a Cisco router represent where much of the real magic takes place.

Think of a Cisco router are being really no more than a specialized computer running a custom operating system. In this case, it is a computer optimized to provide routing and related functions. Instead of relying on a hard disk for storage, a Cisco router relies on different types of memory, each with a different purpose. In this article we’ll take a look at each of these different storage areas, and the functions they’re responsible for.

There are four main memory areas within a Cisco router that it’s important to be familiar with, namely Flash, RAM, ROM, and NVRAM.

Flash Memory (where the IOS stored)

Flash memory is implemented (on a Cisco 2500) using two Single Inline Memory Module (SIMM) slots that hold erasable programmable read-only memory (EPROM). Flash memory is used to store and run the Cisco IOS software – the router’s operating system. When a router is powered down, the contents of Flash memory are not lost. However, its contents can be upgraded by “flashing” the chip, not unlike one can do with a BIOS in the PC world. While a router is running, the contents of Flash are set to a read-only mode.

Flash memory for a Cisco 2500 series router ranges in size from a minimum of 4MB up to a maximum of 16MB. You might consider adding additional Flash memory to meet the space requirements of the IOS version that you have chosen to run. For a Cisco 2501, the base IP version of IOS 12.0 requires a minimum of 8MB of Flash memory. So, if you had a Cisco 2501 that shipped with only 4MB of Flash, you would require at least one additional 4MB SIMM. For IOS versions with more advanced feature sets, it is not uncommon to require at least 16MB of Flash.
When installing or upgrading Flash using multiple SIMMs, it is important to note that they must be the same size. For example, if you already have 4MB of Flash and wish to upgrade, you can either replace the 4MB SIMM with an 8MB SIMM, or simply add a second 4MB SIMM. You cannot mix and match SIMMs with different storage capabilities. As such, you cannot have one 4MB and one 8MB SIMM installed at the same time – their storage capabilities must equal.

RAM (where routing table, arp table, buffering, etc located)

Random Access Memory (RAM) represents the non-permanent or volatile working area of memory on a Cisco router. When the router is powered down, the contents of RAM are lost.

By default, RAM is broken up into two main areas – Main Processor Memory, and Shared I/O Memory. Main Processor Memory is where the routing table, ARP tables, and running configuration are stored. Shared I/O Memory is used as a buffer location for temporarily storing packets prior to processing. Most Cisco 2500 routers will have 2MB of RAM soldered to the system board (this amount, however, depends on the revision number of the router), along with one SIMM slot to add additional RAM. The maximum amount of RAM that can be added to a Cisco 2500 is 16MB. If 16MB is added, that provides a maximum of 18MB of available RAM. In cases where a RAM SIMM is installed, its capacity will be used as Main Processor Memory, while the onboard RAM (2MB) will be used as Shared I/O memory. If no SIMM chip is present, that 2MB of on-board RAM will be split between both areas, providing each with 1MB of working space. This should be avoided for performance reasons.

ROM (POST, BOOTSTRAP, etc)

In older Cisco router models, Read-Only Memory (ROM) chips were used to store the IOS software. In newer models, this is no longer the case. As mentioned previously, the IOS image is now stored in Flash memory (it can also be stored on a TFTP server, as I’ll discuss in the next chapter). ROM is now used as the memory area from which a Cisco router begins the boot process, and is made up of a number of elements. These elements are implemented via microcode, a set of programming instructions that are contained in ROM.

On Cisco 2500 series routers, ROM is 2MB in size. In cases where ROM needs to be upgraded (which is rare), the actual chips needs to be replaced on the router’s motherboard. When a router is powered down, the contents of ROM are always retained.

NVRAM (where configuration file stored)

Non-Volatile Random Access Memory (NVRAM) is used as the storage location for the router’s startup configuration file. After the router loads its IOS image, the settings found in the startup configuration are applied. When changes are made to a router’s running configuration, they should always be saved to the startup configuration (stored in NVRAM) or they will be lost when the router shuts down. Remember that the running configuration is stored in RAM, which is erased when the router is powered down. On a Cisco 2500 series router, NVRAM is a relatively tiny 32KB in size.
Knowing what’s going on where is an important part of not only understanding how a Cisco router operates, but will also help to determine the source of problems or issues, should the need arise. Remember – just because something can’t be seen, that doesn’t mean it’s not important.