Testing IPv6

I've been testing IPv6 Internet access at home using following tunneling modes.
1. 6to4 Automatic Tunnel via Public 6to4 Relay (using Cisco IOS)
2. 6in4 Tunnel using Tunnel Broker (using Cisco IOS)
3. Teredo Tunnel (using Windows 7)

I found using Tunnel Broker (option 2) the most reliable solution.

Following equipments were used in the test.
1. Cisco 1841 Router Running 12.4 code
2. Windows 7 Computers x 2
3. Ubuntu 4.1.2

F0/0 is connected to the Internet.
F0/1 is connected to the Internal Network.

IOS config using Tunnel Broker (Hurricane Electric).

interface FastEthernet0/0
description Outside
ip address dhcp

interface FastEthernet0/1
description Inside
ip address 192.168.2.1 255.255.255.128
ipv6 address 2001:470:1FFF::1/64 <-- HE gave out free /64 blocks
ipv6 enable

interface Tunnel0
description Hurricane Electric IPv6 Tunnel Broker
no ip address
ipv6 address 2001:470:1FFE::1/64
ipv6 enable
tunnel source [my public IP]
tunnel destination [Hurricane Electric assigned IP]
tunnel mode ipv6ip

ipv6 route ::/0 Tunnel0

Once config was completed (and half a day of troubleshooting), I was able to run following tests.
1. ping test to ipv6.google.com, www.ipv6forum.com (ping -6 in Windows and ping6 in Linux)
2. Browse to http://www.kame.net and I saw a dancing Turtle :)
3. Go to http://whatismyv6.com/ and check out my IPv6 addr.

Notes on Windows 7
I ended up having multiple IPv6 addresses on one interface.
1. Link local starting with FE80, but I have to keep this address.
2. Static IPv6 that I assigned manually. I want this address to be the only global IPv6 address.
3. One random IPv6 address assigned by OS.
4. Another temporary IPv6 address.

(I was able to get rid of v6 address in 3 and 4 by disabling RouterDiscover using the following command.

netsh interface ipv6 set interface "Local Area Connection" routerdiscovery=disabled

ref: http://technet.microsoft.com/en-us/library/bb726952.aspx

Notes on Linux (CentOS/RedHat)

Following config was used
1. to assign static IPv6 address to eth0 and
2. to disable stateless autoconfig.

[mid@rdis100 network-scripts]# more /etc/sysconfig/network-scripts/ifcfg-eth0
DEVICE=eth0
BOOTPROTO=static
DHCPCLASS=
HWADDR=00:0C:29:DA:50:FE
ONBOOT=yes
IPADDR=192.168.2.121
GATEWAY=192.168.2.1
NETMASK=255.255.255.128
IPV6INIT=yes
IPV6ADDR=2001:470:1F07:BAE:0000:0000:0000:121
IPV6_DEFAULTGW=2001:470:1F07:BAE:0000:0000:0000:1

[mid@rdis100 network-scripts]# more /etc/sysconfig/network
NETWORKING=yes
NETWORKING_IPV6=yes
IPV6_AUTOCONF=no
HOSTNAME=rafa.connectionless.net

[mid@rdis100 network-scripts]# ip -6 address show dev eth0
2: eth0: mtu 1500 qlen 1000
inet6 2001:470:1f07:bae::121/64 scope global
valid_lft forever preferred_lft forever
inet6 fe80::20c:29ff:feda:50fe/64 scope link
valid_lft forever preferred_lft forever

Notes on Linux (Ubuntu)

Following config was used
1. to assign static IPv6 address to eth0 and
2. to disable stateless autoconfig.

[mid@rds001 network-scripts]# more /etc/network/interfaces
auto lo
iface lo inet loopback

auto eth0
iface eth0 inet static
address 192.168.2.105
netmask 255.255.255.128
gateway 192.168.2.1


### Start IPV6 static configuration
iface eth0 inet6 static
pre-up modprobe ipv6
address 2001:470:1f07:bae::122
netmask 64
gateway 2001:470:1f07:bae::1
### END IPV6 configuration

[mid@rds001 network-scripts]# sysctl -w net.ipv6.conf.eth0.autoconf=0

[mid@rds001 network-scripts]# /etc/init.d/networking restart

JUNOS 101 #2

#2 OSPF
1. Establish OSPF neighbors between EX-8216 over 10G link (area 0)
2. Configure Vlan1 in ospf area 1.

switch #1

protocols {
ospf {
area 0.0.0.0 {
interface xe-0/0/0.0;
}
}
}

interfaces {
xe-0/0/0 {
unit 0 {
family inet {
address 2.2.2.1/30;
}
}
}
}

switch #2

protocols {
ospf {
area 0.0.0.0 {
interface xe-0/0/0.0;
}
area 0.0.0.1 {
interface vlan.1;
}
}
}

interfaces {
xe-0/0/0 {
unit 0 {
family inet {
address 2.2.2.2/30;
}
}
}
}

interface {
vlan {
unit 1 {
family inet {
address 1.1.1.1/24;
}
}
}
}

JUNOS 101 #1

I got a few Juniper boxes to test, 2 x EX-8216 and a few pizza boxes. This is the first time I am working on Junos boxes. These are configuration notes from my first days with Junos on EX-8216.

#1 BGP
Following configuration is
1. Establish a BGP session between two EX-8216
2. Redistribute static route into BGP

Switch #1

interfaces {
xe-0/0/0 {
unit 0 {
family inet {
address 2.2.2.1/30;
}
}
}
}

routing-options {
static {
route 20.20.20.0/24 next-hop 192.168.14.1;
}
router-id 2.2.2.1;
autonomous-system 1;
}

protocols {
bgp {
group ToAS2 {
type external;
family inet {
unicast;
}
export Static;
peer-as 2;
neighbor 2.2.2.2;
}
}
|

policy-options {
policy-statement Static {
term static {
from protocol static;
}
then accept;
}
}


crusader@j-testms1-re0# run show bgp summary
Groups: 1 Peers: 1 Down peers: 0
Table Tot Paths Act Paths Suppressed History Damp State Pending
inet.0 0 0 0 0 0 0
Peer AS InPkt OutPkt OutQ Flaps Last Up/Dwn State|#Active/Received/Accepted/Damped...
2.2.2.2 2 26364 26345 0 0 1w1d5h 0/0/0/0 0/0/0/0

[edit]
crusader@j-testms1-re0#

Switch #2

interfaces {
xe-0/0/0 {
unit 0 {
family inet {
address 2.2.2.2/30;
}
}
}
}

routing-options {
router-id 2.2.2.2;
autonomous-system 2;
}


protocols {
bgp {
group ToAS1 {
type external;
family inet {
unicast;
}
peer-as 1;
neighbor 2.2.2.1;
}
}
}

crusader@j-testms2-re0# run show bgp summary
Groups: 1 Peers: 1 Down peers: 0
Table Tot Paths Act Paths Suppressed History Damp State Pending
inet.0 3 1 0 0 0 0
Peer AS InPkt OutPkt OutQ Flaps Last Up/Dwn State|#Active/Received/Accepted/Damped...
2.2.2.1 1 26346 26366 0 0 1w1d5h 1/3/3/0 0/0/0/0

[edit]
crusader@j-testms2-re0#

[edit]
crusader@j-testms2-re0# run show route protocol bgp

inet.0: 9 destinations, 11 routes (9 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both

2.2.2.0/30 [BGP/170] 1w1d 05:38:45, localpref 100
AS path: 1 I
> to 2.2.2.1 via xe-0/0/0.0
20.20.20.0/24 *[BGP/170] 1w1d 05:38:45, localpref 100
AS path: 1 I
> to 2.2.2.1 via xe-0/0/0.0
192.168.14.0/24 [BGP/170] 1w1d 05:38:45, localpref 100
AS path: 1 I
> to 2.2.2.1 via xe-0/0/0.0

inet6.0: 2 destinations, 2 routes (2 active, 0 holddown, 0 hidden)

Network CLI Utilities

Shows the multicast groups that the host already joined in

netstat -ng (Linux)
netsh interface ip show joins (Windows / RRAS service needs to be enabled and started)

Shows UDP/TCP/IP statistics

netstat -su (Linux)
netstat -st (Linux)
netsh interface ip show udpstats (Windows)
netsh interface ip show tcpstats (Windows)
netsh interface ip show ipstats (Windows)

ping+traceroute on steroids
lft (Linux - stands for Layer4 traceroute)
pathping (Windows)

Network OSs

Network equipment vendors, especially Cisco, are making a variety of hardware platform and thus they are having a hard time keeping uniform OS across the board. Here are a few articles that I read lately -

1. Michael Morris
http://www.networkworld.com/community/node/42294

2. Q&A with Scott Kriens (It's the operating system, stupid!)
http://www.networkworld.com/news/2008/013008-juniper-kriens.html

3. IOS vs JUNOS
http://features.techworld.com/storage/4066/ciscos-ios-vs-junipers-junos/?print

Excerpts from 1.

Back when I worked in network operations at AT&T, I was (strangely) proud that I knew all the different versions, feature sets, and varieties of Cisco IOS. It was one of the things I could use quickly when dealing with bugs and outages. However, now, all the different versions of IOS are making me sick. Especially now being a manager having to deal with all of them.

Let's take a short stroll down IOS lane...

Best I can tell there are nine varieties of IOS:

1. Regular IOS - the old warhorse running the routers.
2. IOS for 6500s and 7600s - this is different than "regular IOS" since it has specific versions and release tracks. (12.2(33)SXI is the latest strain.)
3. Modular IOS for 6500s and 7600s - same as above, but now "modular".
4. IOS for 3750 and 3550s - again, IOS-like but with a completely different release model and versions.
5. IOS XE for the ASR line - an abstracted version of IOS that runs the IOS shell in a process along with all other hardware functions.
6. IOS XR for the BFRs
7. NX-OS for the new Nexus line of switches - based on SAN-OS, but used in Ethernet switches. It actual has two different lines - one for the Nexus 7000 and another for the Nexus 5000.
8. Cisco IOS for ASAs
9. IOS for CSM, ACE, and other service blades

So, that's nine different varieties of IOS. Then, of course, you can divide each line into its various versions. In good old IOS there's the ISRs, the 7200s, and 7300s. For each hardware line there's a version line - 12.1, 12.2, 12.3, and 12.4 (or vice-versa, for each version line there is a hardware line). Inside the versions there's mainline, T-code, and special releases. There are also qualifiers like FCS, LD, GA, and GD...but, last year, those went away and now we have MD.

So, just for regular IOS, let's do some math:

4 versions * 3 hardware lines * 3 release modes * 5 qualifiers = 180 different versions

AHHHHHH!

Oh, wait, I forgot the feature sets. You know, the very clear and simple to understand different capability varieties you can order - Enterprise, Advanced Enterprise, Advanced IP Services, IP Services, Advanced Security, IP Voice, plus crypto versions. Probably a good 10 different varieties here. That brings us to 1,800 different versions....just for "regular IOS".

OSPF Reference Bandwidth in NX-OS (4.1(5))

To control how Open Shortest Path First (OSPF) calculates default metrics for an interface, use the auto-cost command. To assign the default reference bandwidth of 40Gb/s, use the no form of this command.

auto-cost reference-bandwidth bandwidth [Gbps | Mbps]

Defaults

40 Gb/s. The bandwidth defaults to Gb/s if you do not specify the Gpbs or Mbps keyword.

I wonder why Cisco is leaning towards 40G instead of 100G.
One would think that Cisco will sell 40G linecards to the customer and .... a few months later the same customer has to buy 100G linecards.

14th is a sweet number

Congratulations Roger. You are the best .. of all time !!!


Roger and Andre

I think Roger will regain No.1 ranking before the end of the year.

Nexus 7000 Notes - 4 (from test lab)

"write mem" (or any write command for that matter) is gone.

"copy run star" take approx 15 seconds to write the config and idle for another 35 seconds (exactly) before returning to the command. (have to figure out what is going on during that time)

Nexus no longer supports PagP. It is either LACP or EtherChannel.

OSPF process can either be a number or a name i.e. supports alpha-numeric OSPF process ID. OSPF network statements are now configured per interface basis instead of in router configuration. Not sure if it a good thing since OSPF network statements are scattered all over the places.

"show process cpu history" is gone.
"show process cpu" shows unfamiliar processes (looks like link processes). My co-worker says Cisco fixed high CPU problem by not showing the numbers to the users - at least with a familiar command.

Nexus 7000 Notes - 3 (commands - this list will grow)

(It seems like command reference for NX-OS 4.1 on CCO is not completed. All the commands with * are missing - not that they look like undocumented commands.).

show hardware fabric-utilization timestamp *
- gives peak fabric utilization time stamp. In 6500, timestamp option was not available.

show hardware capacity *
- gives a lot of useful information including the command above

show port-channel traffic
- gives utilization of each link in a port channel

show license host-id
- do not forget when activating license !!

Nexus 7000 Notes - 2 (Linecards)

Nexus linecards come with an integrated M series engine. The first generation for forwarding engine is referred to as M1 forwarding engine. M1 can deliver 60Mbbps of L2 and L3 IPv4 unicast forwarding. (30Mpps of IPv6) across all ports on a single linecard. 10-slot chassis with 8 M1 forwarding engines delivers up to 480 Mpps of IPv4 unicast forwarding. (Sup720 claims up to 400Mpps).

32 ports 10G card (N7K-M132XP-12)
Part number can be dissected as follows -
N7K - for Nexus 7000
M1 - forwarding engine
32 - number of ports
X - - port speed (in Roman ?)
P - ??
1 - fabric version
2 - number of fabric required for full bandwidth (w/o redundancy)

Each fabric connection is 40Gpbs (dCEF720 has 20Gbps) with maximum of 2 fabric connectors. N7K-M132XP-12 has 2 fabric connections (i.e 80Gbps bandwidth to fabric) and makes it 4:1 oversubscription for a fully populated line card. The card can be run in non-oversubscribed mode by dedicating fabric access to 1 port in each port block. First port in each port block of 4 will become dedicated port - port 1,2,9,10,17,18,24,25.
"rate-mode dedicated" interface command is used to make the first port in port group in dedicated mode - the rest of the ports in port block are disabled.


48 ports 1G card (N7K-M148GS-11 or N7K-M148GT-11)
N7K - for Nexus 7000
M1 - forwarding engine
48 - number of ports
G - - port speed (in Roman ?)
S/T - S for SFP and T for copper ?
1 - fabric version
1 - number of fabric required for full bandwidth (w/o redundancy)

48 ports linecard has 40Gbps fabric access and thus it is 1:1.2 oversubscribed.

Nexus 7000 Notes - 1

I just got my hands on Nexus 7010 last week.
First thing that I noticed is that the box is very deep. Its back is protruding towards the aisle between data center rows.
It is 33.1" deep (as opposed to 6509's 18.2").

Nexus decouples fabric from the supervisor and the fabric is scalable (can be upgraded up to 5 fabric modules). Fabric cards are inserted from the back.
It has front-bottom to read-top air flow.

There are -
- 2 fan tray for supervisor and linecards (6 fans in each tray)
- 2 fan for fabric.
All the fans are hot-swappable.

Cisco claims first generation fabric linecard (N7K-C7010-FAB-1) can forward 46Gpbs - thus fully populated 5 fabric cards can forward up to 46 x 5 = 230Gbps.
Currently shipping supervisor 1 bandwidth is 115Gpbs/slot and the bandwidth of I/O linecard is 230Gbps.

According to Cisco maths, 7010 has maximum bandwidth of -
230Gbps / slot x 8 slots = 1840Gbps (I/O linecard)
115Gbps / slot x 2 slots = 230Gbps (sup)
(1840 + 230) x 2 (for full duplex operations) = 4.1 Tbps system.

(6500 with sup-720 is, as it name applies, a 720Gbps system.)

Buffers, Queues and Thresholds

When QoS is enabled on a 65xx switch, queues are automatically allocated based on architecture of the line card.

For example -
1p3q8t for 6748 and 6724 (10/100/1000 linecard)
1p7q8t for 6704 (4 ports 10G card)
1p7q4t for 6708 (8 ports 10G card)

Queue size, numbers and architecture are different based on line card.
Here is the detail list as of 2009.

show queueing interface command will give away a lot of information about the port and the linecard.

Queue configuration is applied to a block of ports per ASIC (Rohini on 6724 and 6748). For 6724, wrr algorithm and qos-map configuration applied on one port will affect all 12 ports of the same ASIC, and for 6748 all 8 ports of the same ASIC.

"default interface" on one of the ports will reset wrr allocation of queues but not the qos-map, if it were altered from default *

Beyond STP

Several enhancements were made to the layer 2 loop prevention mechanism, the original STP (IEEE 802.1d). Examples are multiple spanning tree, rapid spanning tree.
One of the major drawbacks of spanning tree is - it prohibits the use of multiple paths in layer 2. After BPDU exchange, STP will put redundant ports in blocking mode.

Earlier solutions to disable SPT and to take advantage of multiple layer 2 paths were the use of PortChannel - FEC or GEC (Proprietary), PagP (Proprietary) and LACP (802.3ad, later 802.3AX).

Biggest limitation of PortChannel is that it can only be used between two adjacent devices.

Cisco came up with vPC (virtual PortChannel) in its Nexus platform (NX-OS) which will let multiple active layer 2 paths exist. See here for detail explanation.

vPC is Cisco solution before a standard based technology is agreed upon. That technology is in work in progress for a few years (since 2007 I think) and it has a weird sounding acronym. It is IETF's TRILL - Transparent Interconnection of Lots of Links. TRILL uses IS-IS (yes that L3 routing protocol) to manage L2MP management traffic.

L2MP - Layer 2 MultiPath

ASICs

- "show asic-version slot x" will show the count of ASICs like Rohini (Port ASIC), Janus (Fabric interface)

Took it from here.
There is no oversubscription built in to the Rohini-Janus interconnect. The oversubscription on these cards is from janus to the fabric. Also intra Janus there is a 26Mpps limitation.

To elaborate, 6748-GETX is as you say, 1-12, 13-24, etc. The port mapping for the fiber version of 6748, and for 6724, is a bit different, it is even & odd (so eg, 1-23 odd, 2-24 even, etc) but yes it is 12 ports per rohini in all cases.

WRT oversubscription, again, the oversub is at the fabric level, not the port level as you would see on some 4500 series cards & on the 6500 series 6148-GETX etc.

Notes on 6708

- There are 2 flavors - 3C and 3CXL.
- 6704 has 16MB per port buffer, 6708 has 200MB per port buffer
- 8 x 10G ports with 40Gbps (2 x 20Gbps) to Fabric (2:1 fabric oversubscription ?)
- 64Gbps local switching (1.25:1 local oversubscription ?)
- 48Mpps switching
- "no hw-module slot x oversubscription" will turn off oversubscription, effectively shutting down port 3,4,7 and 8.
- in non-oversubscribed mode, port 3,4,7 and 8 cannot be unshut and "show interface" output will be "disabled for performance" instead of normal admin disable
- "mac-address-table synchronize" is enabled by default (and fix PFC/DFC MAC synchronization problem )

Gulbis thumps Djokovic in Aussie Warmup

Final score = 6-4, 6-4
Both players made too many unforced errors. Djokovic uncharacteristically committed too many double faults and he looked flat throughout both sets.

This result means that Federer will maintain world number 2 ranking and most likely will be seeded number 2 in Australian Open.

So far, Andy Murray seems to be the best among top 4.

Yonex RDS 001 Midplus Spec

Head Size:
98 sq. in. / 632 sq. cm.

Length:
27 inches / 69 cm
Strung Weight: 11.7oz / 332g

Balance:
8pts Head Light
Swingweight: 322

Stiffness:
68

Beam Width: 18-21 mm

Composition:
High Modulus Graphite / Elastic Ti

String Pattern:
16 Mains / 19 Crosses

Big Ruby ?

This is from the movie "The Dark Knight", a huge blockbuster in 2008 summer.


- Low Resolution Video Clip -



- High Resolution Video Clip -

On DVD, this scene is at a few seconds after the beginning of the chapter 14, around 53min 23secs. The dialogue goes like this -


Alfred Pennyworth (Michael Caine):
A long time ago, I was in Burma, my friends and I were working for the local government. They were trying to buy the loyalty of tribal leaders by bribing them with precious stones. But their caravans were being raided in a forest north of Rangoon by a bandit. So we went looking for the stones. But in six months, we never found anyone who traded with him. One day I saw a child playing with a ruby the size of a tangerine. The bandit had been throwing them away.

Bruce Wayne (Christian Bale) :
Then why steal them?

Alfred Pennyworth (Michael Caine):
Because he thought it was good sport. Because some men aren't looking for anything logical, like money. They can't be bought, bullied, reasoned or negotiated with. Some men just want to watch the world burn.


The first time I heard the line, I laughed.
And then I think, the script writer got the stories about Burma all mixed up.
May be, the kid playing with big buby is a grandson of one of those generals.

One thing is right though - there are men in Burma who just want to watch the rest of the country burn or drown as long as they can hold on to the power.

CEF ျပသနာ

ဒီျပသနာၾကဳံတာ ဒီလထဲမွာ အနည္းဆုံး ၃ ခါရွိျပီ။ Cisco layer-3 switch ေတြမွာ CEF နဲ႔ MLS ကုိသုံးရင္ (default is on) CEF ဇယား ၂ ခုေဆာက္ရတယ္။ တစ္ခုက Hardware table ျဖစ္ျပီး၊ တစ္ခုက Software table ျဖစ္ပါတယ္။ ဒီဇယားႏွစ္ခုက Packet တစ္ခု ဘယ္ကုိသြားခ်င္ရင္ ဘယ္ကတဆင့္သြားမယ္ဆုိတာ ဆုံးျဖတ္တာျဖစ္တယ္။ တနည္းေျပာရင္ Source နဲ႔ destination address ကုိသိရင္ next hop address ကုိဆုံးျဖတ္တာေပါ့။ အဲဒီ Hardware table နဲ႔ Software table သေဘာမတူၾကေတာ့အခါ ျပသနာ မ်ဳိးစံု တက္ေတာ့တာပါဘဲ။

ဒီဥပမာမွာ Source address (10.50.16.11) ကေန destination address (10.100.6.1) နဲ႔ (10.100.6.2) ကုိသြားတဲ့လမ္းေၾကာင္းကုိမွတ္ထားတဲ့ hardware table နဲ႔ software table သေဘာမတူျဖစ္ေနတာကုိ ေတြ႔ပါလိမ့္မယ္။

switch က Cisco 6500 Supervisor-720 ျဖစ္ပါတယ္။

့hardware cef entry ကုိၾကည့္ဖုိ႔ command - "show mls cef exact-route "
software cef entry ကုိၾကည့္ဖုိ႔ command - "show ip cef exact-route "

"show ip route" မွာေရာ၊ software cef table မွာပါ next-hop က 10.50.252.26 လုိ႔ေျပာျပီး - hardware cef table မွာေတာ့ 10.100.6.2 အတြက္ nexthop က 10.50.252.38 လုိ႔ ေျပာပါတယ္။ တကယ္တန္း packet က hardware cef table ကေျပာတဲ့ လမ္းေၾကာင္းအတုိင္းသြားပါတယ္။

lab-router#sh ip route 10.100.6.1 Routing entry for 10.100.6.0/24 Known via "bgp 65050", distance 200, metric 0 Tag 65005, type internal Last update from 10.22.1.57 03:50:24 ago Routing Descriptor Blocks: * 10.22.1.57, from 10.50.252.26, 03:50:24 ago Route metric is 0, traffic share count is 1 AS Hops 1 Route tag 65005 lab-router#sh ip route 10.100.6.2 Routing entry for 10.100.6.0/24 Known via "bgp 65050", distance 200, metric 0 Tag 65005, type internal Last update from 10.22.1.57 03:50:26 ago Routing Descriptor Blocks: * 10.22.1.57, from 10.50.252.26, 03:50:26 ago Route metric is 0, traffic share count is 1 AS Hops 1 Route tag 65005 lab-router# lab-router#show ip cef exact-route 10.50.16.11 10.100.6.0 10.50.16.11 -> 10.100.6.1 : GigabitEthernet6/1 (next hop 10.50.252.26) lab-router#show ip cef exact-route 10.50.16.11 10.100.6.1 10.50.16.11 -> 10.100.6.2 : GigabitEthernet6/1 (next hop 10.50.252.26) lab-router# lab-router#show mls cef exact-route 10.50.16.11 10.100.6.1 Interface: Gi6/25, Next Hop: 10.50.252.38, Vlan: 1020, Destination Mac: 0022.55e6.66d1 lab-router#show mls cef exact-route 10.50.16.11 10.100.6.2 Interface: Gi6/1, Next Hop: 10.50.252.26, Vlan: 1018, Destination Mac: 0022.55e6.67f1 lab-router#

ဒီျပသနာကုိ Cisco website မွာ ဒီမွာရွင္းျပထားေပမဲ့ ေရးထားကတလြဲျဖစ္ေနပါတယ္။
အမွန္ကေတာ့ ေအာက္ကစာပုိဒ္အတုိင္းျဖစ္သင့္တယ္လုိ႔ထင္ပါတယ္။ ေနာက္ဆုံးစာေၾကာင္းက မွားေနတာပါ။

Difference Between IP CEF and MLS CEF The output of show mls cef exact-route source-ip address dest-ip address and show ip cef exact-route source-address dest-ip address is different because the packets are software switched when IP CEF is used, and the packets are hardware switched when MLS CEF is used. Because most of the packets are hardware switched, the best command to view the next-hop to reach a destination is show mls cef exact-route source-ip address dest-ip address .

Huck

ျပင္သစ္ဘုရင္လူ၀ီ ၁၆ ေခါင္းျဖတ္ခံရျပီး သူရဲ့သားအၾကီးဆုံးမင္းသားလဲ ဘုရင္ျဖစ္ရမဲ့အစား ေထာင္ထဲမွာ ပိတ္ထားခံရတဲ့အေၾကာင္း၊ တခ်ဳိ.ကေျပာၾကတာေတာ့ မင္းသားေထာင္ထဲမွာ ေသသြားတဲ့အေၾကာင္း ကၽြန္ေတာ္က လူမဲ ဂ်င္ကုိ ေျပာျပပါတယ္။

လူမဲ ဂ်င္ - "သနားစရာဘဲ"
ဟတ္က္ဘယ္ရီ - "ဒါေပမယ့္ တခ်ဳိ.ကေျပာၾကတာက ေထာင္ကလြတ္ျပီး အေမရိကကုိ ေရာက္လာသတဲ့"

လူမဲ ဂ်င္ - "ဒါဆုိေကာင္းတာေပါ့! ဒါနဲ႔ သူတစ္ေယာက္ထဲျဖစ္ေနမွာေပါ့ - ဒီမွာ ဘုရင္ဆုိတာမွ မရွိတာ၊ မဟုတ္ဘူးလား ?"
ဟတ္က္ဘယ္ရီ - "မရွိဘူး"

လူမဲ ဂ်င္ - "ဒါဆုိ ဘယ္အဆင္ေျပမလဲ၊ သူဘယ္ေရာက္သြားလဲ?"
ဟတ္က္ဘယ္ရီ - "မေျပာတတ္ဘူး။ တခ်ဳိ.ကေျပာတာေတာ့ ရဲအဖမ္းခံလုိက္ရတယ္တဲ့၊ တခ်ဳိ.ကလဲ ဒီကလူေတြကို ျပင္သစ္စကားေျပာတာ နားလည္ေအာင္ သင္ေပးတယ္ တယ္တဲ့။"

လူမဲ ဂ်င္ - "ဘာေၾကာင့္လဲ ဟတ္က္? ျပင္သစ္လူမ်ဳိးေတြ ငါတုိ႔လုိ စကားမေျပာၾကလုိ႔လား?"
ဟတ္က္ဘယ္ရီ - "ဘယ္ေျပာမလဲ ဂ်င္ - မင္းဆုိလည္းသူတုိ႔ေျပာတာနားလည္မွာ မဟုတ္ဘူး။ စကားလုံးတစ္လုံးေလးမွ နားလည္မွာ မဟုတ္ဘူး"

လူမဲ ဂ်င္ - "ဒါဆုိရင္ေတာ့ ငါေတာ္ေတာ္အျမင္ကတ္မွာဘဲ။ ဘာေၾကာင့္ ဒီလုိျဖစ္ရတာလဲ။"
ဟတ္က္ဘယ္ရီ - "ငါလဲ မေျပာတတ္ဘူး။ ဒါေပမယ္ အဲလုိျဖစ္ေနတာေတာ့ ေသခ်ာတယ္။ သူတုိ႔ေျပာတဲ့စကားနည္းနည္း စာအုပ္တစ္အုပ္ထဲမွာ ဖတ္ဖူးတယ္။ ဆုိပါစုိ႔ တစ္ေယာက္ကလာျပီး Polly-voo-franzy လုိ႔ေျပာရင္ မင္းဘာလုိ႔ထင္မလဲ"

လူမဲ ဂ်င္ - "ငါ ကေတာ့ဘာမွထင္မွာမဟုတ္ဘူး။ ေခၚတဲ့ေကာင္ရဲ့ ေခါင္းကုိသာ ရုိက္ခြဲျပစ္လုိက္မယ္။ အဲဒီေကာင္က လူျဖဴမဟုတ္ဘူး ဆုိရင္ေပါ့။ ဘယ္လူမဲကမွ ငါ့ကုိ အဲဒီလုိ ေခၚတာ မခံႏုိင္ဘူး။"
ဟတ္က္ဘယ္ရီ - "ခ်ီးမွဘဲ၊ မင္းကုိ ဘယ္လုိမွေခၚတာမဟုတ္ဘူး။ မင္း ျပင္သစ္စကားေျပာတတ္သလားလုိ႔ေမးတာ။"

လူမဲ ဂ်င္ - "ဒါဆုိလဲ ဘာေၾကာင့္ အဲလုိ မေမးသလဲ?"
ဟတ္က္ဘယ္ရီ - "သူက အဲလုိေမးေနတာဘဲ။ ျပင္သစ္လူမ်ဳိးေမးတဲ့ နည္းနဲ႔ေမးေနတာ။"

လူမဲ ဂ်င္ - "ဟင္း - ေတာ္ေတာ္ရီစရာေကာင္းတဲ့နည္းဘဲ။ ေတာ္ျပီ ငါဒီအေၾကာင္းထပ္မၾကားခ်င္ေတာ့ဘူး။ အဓိပၸါယ္ကုိ မရွိဘူး"
ဟတ္က္ဘယ္ရီ - "ဂ်င္ ဒီမွာၾကည့္၊ ေၾကာင္ေတြ ငါတုိ႔စကားေျပာသလုိ ေျပာလား?"

လူမဲ ဂ်င္ - "ဟင့္အင္း၊ ေၾကာင္ေတြက ဘယ္ေျပာလိမ့္မလဲ"
ဟတ္က္ဘယ္ရီ - "ႏြားဆုိရင္ေကာ ?"
လူမဲ ဂ်င္ - "ဟင့္အင္း၊ ႏြားလည္းတူတူဘဲ ဘယ္ေျပာလိမ့္မလဲ"
ဟတ္က္ဘယ္ရီ - "ႏြားကေရာေၾကာင္လုိစကားေျပာသလား၊ ဒါမမဟုတ္ ေၾကာင္ကေရာ ႏြားလုိစကားေျပာသလား?"
လူမဲ ဂ်င္ - "ဟင့္အင္း၊ ဘယ္ေျပာလိမ့္မလဲ"
ဟတ္က္ဘယ္ရီ - "သူတုိ႔ဘာသာ စကားတစ္မ်ဳိးဆီေျပာၾကတယ္ဆုိတာ သဘာ၀က်တယ္၊ မဟုတ္ဘူးလား?"
လူမဲ ဂ်င္ - "ဟုတ္တာေပါ့"
ဟတ္က္ဘယ္ရီ - "ေကာင္းျပီ၊ ဒါဆုိ ျပင္သစ္လူမ်ဳိးက ငါတုိ႔နဲ႔မတူတဲ့ စကားေျပာတာသဘာ၀ မက်ဘူးလား? ေျဖပါအုံး"

လူမဲ ဂ်င္ - "ေၾကာင္ကလူလား - ဟတ္က္?"
ဟတ္က္ဘယ္ရီ - "မဟုတ္ဘူး"

လူမဲ ဂ်င္ - "ဒါဆုိ ေၾကာင္တစ္ေကာင္က လူလုိစကားေျပာဖုိ႔ဆုိတာ အဓိပၸါယ္မရွိဘူး။ ႏြားကေရာ လူလား? - ႏြားကေရာ ေၾကာင္လား?"
ဟတ္က္ဘယ္ရီ - "တစ္ခုမွ မဟုတ္ဘူး"

လူမဲ ဂ်င္ - "ေကာင္းျပီ။ ဒါဆုိ ေၾကာင္ေရာ ႏြားပါ သူတုိ႔နဲ႔မဆုိင္တဲ့စကားေျပာစရာအေၾကာင္းကုိမရွိဘူး။ ျပင္သစ္လူမ်ဳိးဆုိတာ လူမဟုတ္ဘူးလား?"
လူမဲ ဂ်င္ - "ဟုတ္တယ္"

လူမဲ ဂ်င္ - "ေကာင္းျပီ! ဒါဆုိဘာေၾကာင့္သူက လူလုိစကားမေျပာရတာလဲ? မင္းဒီေမးခြန္းကုိေျဖပါအုံး"

ဒီလူမဲ အျငင္းအခုံလုပ္ဖုိ႔ဆုိတာ တတ္မွာလဲမဟုတ္ဘူး - ေလကုန္တာသာအဖတ္တင္တယ္။ ဒါနဲ႔ ငါလည္းစကားဆက္မေျပာေတာ့ဘူး။

Mark Twain ရဲ့ "Adventures of Huckleberry Finn" စာအုပ္မွျဖစ္ပါတယ္။
Huck က ၁၃ ႏွစ္သားအရြယ္ျဖစ္ျပီး အိမ္ကေနထြက္ေျပးခါ ေဖါင္တစီးေပၚမာ လူမဲ Jim နဲ႔ ခရီးသြားတဲ့ဇာတ္လမ္းျဖစ္ပါတယ္။ Huck က ျပန္ေျပာတဲ့အေနနဲ႔ ေရးထားတာျဖစ္ပါတယ္။