Yesterday, at my hometown Bukit Mertjam, I received SMS from Singapore and needed to do some trouble shooting with the customer which involved several hours of on the phone conversation.
My uncle's company was kind enough to let me use their PC with Internet connection to do my work. I configured Gizmo project with the secondary account logon to SingNet VOIP SIP server. I then use that to call my customer's mobile phone as he needed to go into the data centre to look at the routers, cables and servers. In this way I saved on the STD call charges and only need to pay for the local call charges incurred from SingNet VOIP account to customer's mobile phone.
Thursday, 20 December 2007
Tcpdump in trouble shooting
Recently, tcpdump help solve two incidents of network issues.
In the first incident, the ADSL router at Pelabohan Tanjung Pelapas warehouse was somehow reset to the factory default without our knowledge. The Indonesian consultant was unable to solve the problem, as he was unable to connect to the Internet, even after changing the network cables.
Fortunately, TMNet static IP subscribers are using PPPoE to get the IP set up instead of aal5snap. We are able to logon to the router with default password from the Internet and found that it was reset to factory setting of 192.168.0.1. The Singaporean engineer was then told to run tcpdump to confirm the connectivity from the firewall machine to the ADSL router. With tcpdump, we were able to confirm that the cable had no problem connecting to the router. Also we could confirm that the router LAN IP address had changed.
The router LAN IP was set according to that given by TMNET remotely using the web interface.
The second incidents was after an inplace upgrade of RedHat 9 to CentOS 5 of a gateway server. After the upgrade, the server was unreachable and unable to access Internet. Again using tcpdump to confirm that the external Interface was working. The traffic on the Thomson Alcatel 610s SDSL router could be seen from the gateway server. The only problem was that we were unable to ping the router. After some time of trouble shooting, we decided to bypass the switch hub and connect the UTP cable directly to the back of the SDSL router. It worked.
In the first incident, the ADSL router at Pelabohan Tanjung Pelapas warehouse was somehow reset to the factory default without our knowledge. The Indonesian consultant was unable to solve the problem, as he was unable to connect to the Internet, even after changing the network cables.
Fortunately, TMNet static IP subscribers are using PPPoE to get the IP set up instead of aal5snap. We are able to logon to the router with default password from the Internet and found that it was reset to factory setting of 192.168.0.1. The Singaporean engineer was then told to run tcpdump to confirm the connectivity from the firewall machine to the ADSL router. With tcpdump, we were able to confirm that the cable had no problem connecting to the router. Also we could confirm that the router LAN IP address had changed.
The router LAN IP was set according to that given by TMNET remotely using the web interface.
The second incidents was after an inplace upgrade of RedHat 9 to CentOS 5 of a gateway server. After the upgrade, the server was unreachable and unable to access Internet. Again using tcpdump to confirm that the external Interface was working. The traffic on the Thomson Alcatel 610s SDSL router could be seen from the gateway server. The only problem was that we were unable to ping the router. After some time of trouble shooting, we decided to bypass the switch hub and connect the UTP cable directly to the back of the SDSL router. It worked.
Tuesday, 18 December 2007
Named Unable to Start Up
Named failed to start up with acl error ..., it was due to multiple copy of named on the server when yum upgrade was interrupted.
Email Server Upgrade
It is important to check the settings before putting the server into production use. Otherwise it will be blacklisted immediately before you have time to set it up.
Lucky Draw Scam
I was one of those lucky persons who won a prize on lucky draw event organized by some China company (Taiwan included) based in Hong Kong. Before that I call to make a survey on mobile phone usage was conducted and a gift was promised to be sent to me with a reference number of AK3328. I was told that I had won the fourth prize of USD50,000 and would get it transfered to my bank account after about an hour after the lady submit to the supervisor. Later the supervisor called to say that as it was too late on Friday afternoon, the fund would be transferred on Monday.
I was overjoyed with that information. I was then 50,000 richer. I was planning what to do with that money. To buy a new TV set, a new set of furniture, new curtain... I was thinking to myself that I had been too mean to myself, keep buying second hand gadgets from yahoo auctions and ebay. Buy outdated Nokia N770 instead of N800, always wait at least one year later to buy those gadgets, so that those gadgets were much cheaper and effordable. Selling them off later in order to use the money to buy new toys. So the next day I went to Sitex 2007 and got myself a new ASUS EEE PC.
After more than a week of waiting, checking my bank account every moment, there was no increase in the amount. I thought it might be a scam and decided to forget about it. Then the lady called, asking why I did not call her since I did not get the money. I told her that since this was the prize I won, I was not in a hurry to get it. She told me that now they have an office in KL and invited me to go visit their office in KL. Menara Telekom, Tingkat 18, Bilik 10, Jln Pantai Baru 50672 KL, Tel +603 86590170. Later, the supervisor called and told me that due to the regulation of preventing money laundering, for fund transfer of more than certain amount, we needed to pay a deposit of 10% and each party pay 5% and it would be refunded to me after that. That amount would be S$3600 plus S$50 for the admin work. I told her that at this time of the year, I was very tight and would like to see whether they could give me a grace period when the situation got better before I transfer the money. She told me that she would discuss with her manager and got back to me later.
I told my colleague about it. She told me that this was a scam and sent me a few web links, one of which is kennysia's blog. I listened to the recording done by him, it sound very similar to that of the supervisor. So I decided to stop hoping for the prize.
The lady called again, I told her that since I did not have money to transfer to them in order to get the prize, I would like to donate the money for charity. She told me that even for that I would have to transfer the money for them to arrange for donation. I told her I gave up because I was afraid of being cheated. She then started to say that you could give up the money because of suspicion but could not defame them. I told her that I did not and put down the phone.
The supervisor called, I told her that the bank told me not to proceed as this is likely to be scam. She said that was attitude problem of the bank staff, they should not be telling me that. I told her that recently our local newspaper was reporting on such cases and terminate the call.
They did not call me any more.
The effect of the event was that I got to feel rich and happy for a few days. Also spend more money as a result of that. It is difficult to achieve that otherwise.
I was overjoyed with that information. I was then 50,000 richer. I was planning what to do with that money. To buy a new TV set, a new set of furniture, new curtain... I was thinking to myself that I had been too mean to myself, keep buying second hand gadgets from yahoo auctions and ebay. Buy outdated Nokia N770 instead of N800, always wait at least one year later to buy those gadgets, so that those gadgets were much cheaper and effordable. Selling them off later in order to use the money to buy new toys. So the next day I went to Sitex 2007 and got myself a new ASUS EEE PC.
After more than a week of waiting, checking my bank account every moment, there was no increase in the amount. I thought it might be a scam and decided to forget about it. Then the lady called, asking why I did not call her since I did not get the money. I told her that since this was the prize I won, I was not in a hurry to get it. She told me that now they have an office in KL and invited me to go visit their office in KL. Menara Telekom, Tingkat 18, Bilik 10, Jln Pantai Baru 50672 KL, Tel +603 86590170. Later, the supervisor called and told me that due to the regulation of preventing money laundering, for fund transfer of more than certain amount, we needed to pay a deposit of 10% and each party pay 5% and it would be refunded to me after that. That amount would be S$3600 plus S$50 for the admin work. I told her that at this time of the year, I was very tight and would like to see whether they could give me a grace period when the situation got better before I transfer the money. She told me that she would discuss with her manager and got back to me later.
I told my colleague about it. She told me that this was a scam and sent me a few web links, one of which is kennysia's blog. I listened to the recording done by him, it sound very similar to that of the supervisor. So I decided to stop hoping for the prize.
The lady called again, I told her that since I did not have money to transfer to them in order to get the prize, I would like to donate the money for charity. She told me that even for that I would have to transfer the money for them to arrange for donation. I told her I gave up because I was afraid of being cheated. She then started to say that you could give up the money because of suspicion but could not defame them. I told her that I did not and put down the phone.
The supervisor called, I told her that the bank told me not to proceed as this is likely to be scam. She said that was attitude problem of the bank staff, they should not be telling me that. I told her that recently our local newspaper was reporting on such cases and terminate the call.
They did not call me any more.
The effect of the event was that I got to feel rich and happy for a few days. Also spend more money as a result of that. It is difficult to achieve that otherwise.
Time of birth
For many years, I do not know the time I was born. Only until yesterday, I looked at my birth certificate and noticed that it was 1:15pm. Information is available but if you do not make any effort to look at it, it is as if not available.
Sunday, 16 December 2007
ASUS Eee PC
After queuing for around 5 hours at the launch of Eee PC at Sitex 2007 on 1st Dec 2007, I got the Eee Pc. To my disappointment, there is a bright dot on the LCD panel, the warranty does not cover zero dead pixel, so I have to bear with it. The immediate response was to sell it off to someone who might be very eager to have one and would not mind the dead pixel. After a little while, I decided to keep it. I love the small size and the light weight.
Coming from a PDA user point of view, this is something more convenient if you want to enter some amount text. I still love the Palm OS based Treo 650 mobile phone, the Maemo based N770. When I know that I am not likely to have to enter much text, I will bring the N770 with me, I will be able to read email, with gtalk and company jabber IM available to chat, using gizmo SIP client to call out. I am also able to run VNC over SSH or VPNC to do remote support. But that is for light use of those utilities.
When it come to heavy use of those utilities, I will definitely take Eee PC with me, as larger screen and keyboard is required. Remote desktop and Citrix client are then available also.
For the moment, as I am trying to see how useful it is as it is bundled, I will not change the OS. I find the dictionary in Easy mode useful for common use, as it has English to English, English to Chinese, Chinese to English lookups. SCIM is pre-installed, unlike on N770.
FBreader is included for ebook reading. I like the fact that it can read both chm and plucker format.
Scrolling using the built-in touch pad is rather difficult for me, I preferred to use the scroll button of a USB mouse.
Typing on it is a bit cram and take quite a while to get use to. The position of the Right Shift key is a bit out, luckily, there is a shell script available to change the position, followed by changing of 4 key tops.
The Huawei E220 USB modem works immediately after running the connection wizard and the DNS settings are fine without additional work. As contrast with OpenSuSE 10.3 and Fedora 8, in both cases, the driver for Vodafone Linux Driver need to be downloaded and installed and the DNS need to be configured manually.
Coming from a PDA user point of view, this is something more convenient if you want to enter some amount text. I still love the Palm OS based Treo 650 mobile phone, the Maemo based N770. When I know that I am not likely to have to enter much text, I will bring the N770 with me, I will be able to read email, with gtalk and company jabber IM available to chat, using gizmo SIP client to call out. I am also able to run VNC over SSH or VPNC to do remote support. But that is for light use of those utilities.
When it come to heavy use of those utilities, I will definitely take Eee PC with me, as larger screen and keyboard is required. Remote desktop and Citrix client are then available also.
For the moment, as I am trying to see how useful it is as it is bundled, I will not change the OS. I find the dictionary in Easy mode useful for common use, as it has English to English, English to Chinese, Chinese to English lookups. SCIM is pre-installed, unlike on N770.
FBreader is included for ebook reading. I like the fact that it can read both chm and plucker format.
Scrolling using the built-in touch pad is rather difficult for me, I preferred to use the scroll button of a USB mouse.
Typing on it is a bit cram and take quite a while to get use to. The position of the Right Shift key is a bit out, luckily, there is a shell script available to change the position, followed by changing of 4 key tops.
The Huawei E220 USB modem works immediately after running the connection wizard and the DNS settings are fine without additional work. As contrast with OpenSuSE 10.3 and Fedora 8, in both cases, the driver for Vodafone Linux Driver need to be downloaded and installed and the DNS need to be configured manually.
Qmail server high load average
The load average of qmail server went above 100 without any messages in the queue. Changing the concurrencyincoming to smaller number resolved the problem and the load average fell to the normal of less than 1.
First Blog
After viewing many blogs and getting information from blogs, it is tempting to put up my own so that others might learn from my experiences. Those experiences might help people who encountered the same issues, saving them time. I might not be able to express myself well but I will try my best to make it understandable to most people.
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